When I got engaged, I vowed to do as many things I could by myself (or with the help of family and friends).  Where I ended up hiring people to do some things that I THOUGHT I might be able to DIY (florist, DJ, Photo Booth), I still did a lot of stuff on my own. 

I learned that even if you really like DIY things, doing too much for your wedding can be very stressful and it is no longer fun.  It is best to know when you are taking on too much and to hire people when necessary.

One quick DIY tip:

Pick a couple fonts and a few graphics that you want to represent the mood and feel of your wedding and don't ever stray from them.  Use them on everything.  I say pick a couple of each so that it isn't overkill...mix it up, make the graphics smaller or bigger, mix the fonts together.  It really ties everything together when it all looks uniform.