First, you've got to find MUSIC THAT SUITS YOUR GROUP. That can mean that the song that you heard another group sound so good doing just may not work for your group. So your first thoughts are dashed to pieces.
You need to find songs that your ACCOMPANIST can manage. Or sometimes you have no regular accompanist, but the other options for accompaniment aren't that great, either.
Your BUDGET is tight, so you either have to use music that already exists in your library stacks or be very creative and frugal.
Seems I've spent my life doing the creative and frugal route. Many times I have searched and searched for that perfect piece for my chorus only to run out of time. So I just wrote one. Or, I didn't have an accompanist, so I just directed from the piano bench. Or I got around not having much in the budget by strategically using music from the library stacks or my own private files and only afforded that one new piece I just had to have.
In the end, PLANNING is a matter of being AWARE of upcoming needs and situations and by using your own CREATIVITY to work things out. It can be done.