It occurred to me some newbs might like having some basic help (are people still making comments like 'can we do longer followme?'), and I'd really love to see more follow-me hacks or yellow remakes or something, so...
A lazy man's longer followme, a sucktastic version (no warp asm used, so, easy-ish for newbies):
Spam showsprite, movesprite and hidesprite everywhere; hide the sprite before you enter a new area via mapconnection or it will bug up (can spawn multiple followers if you have a spawnpoint on next map), if by warp it's fine. Put a spawnpoint next to flyspots and you will not have to worry about the FLY HM whatsoever. Spawnpoints mean if your follower gets lost for whatever-reason (say ledges), you can just go back to the 'showsprite movesprite' spawnpoint and it won't be the end of the world.
Use a surf script and hidesprite beforehand; - no, this doesn't solve the surf HM problem if you use the surf hm, but if you're doing a special yellow remake/homage with, say, surfing pikachu (oh all the memories... -happy sigh-), or are using a ship/raft item or something instead of the HM, that doesn't matter too much.
This method is a total pain in the butt, but, if you feel like you really want to play with followme it will let you. Less work if you arbitrarily decide not to have the follower in most buildings and towns or something like that, or if it's a short hack.
I apologize for my less than fantastic scripting skills, and this method probably isn't very helpful(?) but, here's an example of the hidesprite/showsprite spam, you can even use if you credit:
Long Lost Soldier's Following Script
I hope I put the correct version, I got it working before but that might be an older one.
Surf script, use something like:
setanimation 0x0 0x8004
doanimation 0x9,
NOT special 161 unless you use applymovement on the player, because special 161 just makes you surf in the spot right where you are, whereas do-animation will make you move forward one from the direction you are facing, so you can put it in a place where if you walk on to it you will always face water like a corner, or do some kind of water tile check.
I hope that's helpful.