Well, make sure that the videogame, or whatever content should be famous. If theres some content that no one really knows about, people won't understand it. (i have no idea if that made sense but i tried? )

Make sure that you have alot of people and some good ideas on what to make the funtage on. That should help out alot. If you're not sure on how funtages work and all, search for some videos on youtube.

Special editing, sound effects, etc., all make a great funtage!

Heres a few rules i just thought up
1. Dont use anything thats been done before or overused for example the younoob animation your'll see if you search.

2. Think about what you want to do, weather it be scripted comedy, i.e get some people together to reinact funny scenes from movies (again dont use overused movie scenes)

Or spontaneous funny moments, if your using the gameing genre, you may come across funny moments as your recording throw them together with some appropriate sound effects, or music and can be just as funny

3. Be original, if you do search and look at other funtages, dont take your ideas from them, take tips, no one likes a fanboy.

Hope that helps

Heres my 'spontaneous funtage' recorded in a night of laughs.