Tips for a wedding on a budget?

One of my best friends is getting married next year. She is not a big planner or someone who is really into the whole wedding thing.. so she has enlisted me to help plan it. I’ve been preparing by reading lots of bridal mags and doing research online. She has already selected the venue but nothing else has been decided.

So, my question is, do you have any tips for wedding planning?
Is there anything you wish you had known before you planned yours?
Something special you saw at yours or someone else’s wedding that you thought was unique/creative?
Tips for budgeting? Ways to DIY something rather than pay someone else?
Online or otherwise resources?

Any ideas are certainly appreciated by the bride and myself!