i don't know what your situation is, but believe it or not... a bit of knowledge of theory helps quite a lot before getting your chords together for a song. Depends what type you're after and if you're singin it, what your vocal range is cause you gotta know what key your song is in... Commonly used $hit: if you're in C major use chords like C, Dm, Em, F, G, Am and Bdim and vary them... chuck in some hammer ons and pull offs (which will in most cases turn them into some sort of a sus chord) and you've got yourself a very basic rythem to start with.
G major's also real common. Use chords like: G, Am, Bm, C, D, Em, #Fdim.
Cheers