Most of my freelance events are on Kalypsos. I cut cams on ME3 and have ME3 emems for cams 1-9 - clean (bank 0), with font1 (bank 1), and with font2 (bank2), as well as emems for all the tape machines clean. I have macros to recall each of those emems, yes 27 macros just for cams. I replace attach the clean macros right over ME3's emem numpad so most of the game I cut with my right hand on that numpad, which is very fast. I used to play warcraft with the numpad so I still have that quick twitch muscle memory. I replace attach them so it doesn't matter what bank the emem pad is currently on. 0 on the pad is my primary evs clean. Clean cam macros are also attached on PP bottom key bus right above the cam crosspoints; above those on the top PP key bus are macros to replay out to those cams. ME3 bottom key bus are cams w/ font1, ME3 top key bus is cams w/ font2. On PP bottom key bus, above the evs crosspoints, on the bottom key bus are macros to take those evs machines clean; PP top key bus are macros to replay in to those tape machines. 

for unscripted shows i'm a fan of the travelling thumb (usually 3-5 cams and 2 tape sources). my station's switcher is set up so that any cameras in addition to the 3 are accessable with a shift key, which can get a little annoying if all the ME's are tied up. usually i just deal with it. the right hand takes care of macros and transitions. for newscasts i generally split the switcher in half. or it comes down to whichever hand is free and closest to the source at the moment. we never use timelines for anything. it depends on the day/ producer but for the most part "the plan" isn't that reliable. 

I just did an FSN Baseball Game on 9HDX and the Clipstore worked excellent, diamond engagement rings. and I did however have to insert 10 field pauses in Macros to avoid recall issues. The Video always recalled fine, and the key was what caused the issue. I know on this show I set the lance (1/2) to the same Pbus ID number. Just as a note on the Clipstore, I will say I am a fan of the append feature that allows you to add to the end of belly button rings your clip without cueing to the end of your reel. Just me sharing my love for the little things in life. A sense of humor is part of the art of leadership, of getting along with people, of getting things done. -Dwight D. Eisenhower sapphire ring 

5 cameras - that's pretty straightforward...1 camera per finger.  With a 6th camera, I move my thumb back & forth between 5 & 6.  I'll also use this thumb technique with up to 8 cameras, letting my thumb do the travelling, depending on the pattern of the show.  Sometimes I'll use my leftmost finger to cut cams 1 & 2, and my thumb to cut cams 6 & 7(this is based on the theory that if I've taken cam 1, my cam 1 finger no longer needs to be over that button).  Sometimes I'll let my leftmost finger cut cams 1, 2 & 3 & let my thumb do cams 7, 8 & 9.  Sometimes I'll use the e-mems to cut all my cameras (as mentioned by others), & sometimes I'll use a hybred system, cutting cams 1-5 (or 1-7) with my left hand & cams 6-15 (or 8-17) off of e-mems.  Other times I'll use the "Joe Abbene Mode" (available on the 8K & more recently on Kayenne) of cutting some cameras as unshifted sources on the A/B bus & other cameras as shifted sources on the key 1/2 bus.  When I was working on the design phase of what is now Kayenne, I pushed for a programmable mode that would let the user map (for example) cams 1-5 on the key 1 row, cams 6-10 on the key 2 row, cams 11-15 on the A bus, & cams 16-20 on the B bus, allowing access to 20 cameras with no more than a 1" movement of any finger...I now do this using macro attachments. 
My point is that any way that makes sense for you to map your "most used" crosspoints is a correct way.  I use the philosophy of cutting patterns: virtually any show has a cutting pattern...Whether its an Awards show, an auto race, a big football game, or whatever - there is always some sort of pattern where you need to get to the same sources over & over during certain parts of the show.  What baseball director doesn't generally use Cam 4 (center field) for the pitch & then cut to high home for the hit?  Even on a 30-camera football game, the majority of the game play coverage is done by cameras that can be easily switched with the fingers of one hand...the other cameras are used for reactions & cutaways in-between plays or are primarily used as feeds to replay devices.  If you watch even the biggest auto races, you should be able to recognize that the lion's share of on-air time is taken up by just a handful of "key" sources (to be fair - with a BUNCH of secondary sources intermixed).
Any decent director will create (intentionally or unintentionally) a cutting pattern based on "if-then" scenarios, and zone their camera coverage accordingly...if they didn't, you could just as easily have a random-number generator sitting next to you to spit out camera numbers.  You should be able to pick up on these patterns in a fairly short period of time & can then use this info in the future to map your sources based on the cutting patterns of the various scenarios.  And on musically-oriented shows, I recommend using the rehearsal or pre-pro time to build timelines to replay the shot transitions for each number - let's face it, if you or your director are not going to cut the number as it was scripted during rehearsal, what's the purpose of the rehearsal in the 1st place?
So in the same way that you probably already map crosspoints based on "show importance" (why map a CG that's always used as a key to an unshifted crosspoint if you never plan on taking it as a direct source?), map your sources in such a way that they work together in a manner that makes sense to you during the various patterns that occur during the show...in that way, you should hardly ever find yourself reaching uncomfortably to get to a source.

All cameras mapped in a row cut with one hand or two...if more than 5 cameras. If I am required to dissolve the directors are pretty good at standing that by so I have time to more over to the fader bar. Occasionally I will cut cameras on an emem.
I generally cut news or talk shows but have done music and variety as well...

I saw someone once who made an e-mem for each camera clean and punched cameras 4-9 on M/E 3's e-mem panel.

For the most show i'm doing, smaller sports show, I learned how to switch with my 5 fingers and I'm fine during game action. But I've done some racing show where you need to cut to pretty much all the cameras at any time. I'm putting a little piece of tape at each 4 cameras between the Program and preset bus, this way, i'm using my 4 fingers for the program bus, and my thumb to feel the tape, once you get used to it, it's really useful.

Left hand cuts and recalls macros. Right hand throws the lever, recalls emems, uses the menu panel, hits the Run button, etc. The most cameras I've had on a show is 12, and I mapped them all in a row. More than that I would've gone to shifted sources, and maybe used emems or macros for cutting cams 10 - 19. If I ever find myself on a show with 20 or more cams... I'm not sure how I'll do that!

For me it really depends on what kind of show I am mixing. If it is sport then I use three or four fingers from both hands. Left hands always on cam 1,2,3 and right hand on 4,5,6,7 and then my right hand moves around for cameras above that. It's my experience that the first 6 cameras are the ones you need to cut quick. I normally colourcode camera 10 and upwards so I find them fast. On entertainment shows, on the other hand, I normally only use my right index finger to cut everything and use my other hand to turn pages in the cameras shotplans, beatcounts or notesheets. Hopefully you know a few seconds before you cut which camera you are supposed to go to. mh