Well, it really depends on what sprite you are doing, how big it is and how many and what colors it is/they have. (That's why NES/GB/GBC are pretty easy but still are fun to make.) Beads don't really fuse diagonally, so something like DenDel or TeleTel wouldn't work because of the antennas (unless you made it like a giant square/coaster with them in the middle, or used some clear beads for support.) And, not exactly every color is avaible (but pretty much every one is, or a variation of it) of the beads, so if you want to be like me where everything has to be exact, you might not be able to make some things (like I wanted to make Fungus once, but there's not really any beige colors that I'm aware of
). I haven't tried making any GBA or DS sprites yet because of all of the colors you need for them.
Also, I'd reccomend buying the large connectable boards (colored or clear, but I only have colored), because even some of the tiniest sprite don't fit on the regular (small) square board, which is only 14x14 (in beads/pixels). Since each pixel is equal to one bead, you'll be needing some boards to do certain ones. (Punica only took 2 boards, but there's another non-telefang sprite I want to do and it takes 6 boards -_-).
I also highly reccomend using MS Paint for observing the sprites, because you can put your sprites right on there, zoom in on it, grid the pixels, find out how many boards it takes, etc. (I always use MS Paint for videogame sprites that I'm gonna make, but I'm used to the format of the versions before windows 7.)
As for tips on how to iron it and stuff, I'd just read the instructions and try testing it out on some little things first (but you're supposed to iron both sides, not that everyone does/has too). This is obvious too, but always use a square board
.
And now that I'm finally almost done typing this, yes, I'll take commissions. I enjoy doing these.
(I just wish I could find my cat :'( )