There is a lot of work that you can do on your own. Often you can even find small workshops hosted by Home Depot (or similar) that will demo out "tiling techniques", "proper wall-papering", etc etc. Just ask the folks there and see if they're hosting anything. If you can't find any then just hit the 'net and research what you want to do.
Next, do
not shortcut or short-change anything. One of the worst decisions I saw in a house... a few relatives of mine decided to turn their 2nd den into the main kitchen. (Ripped out the carpet, install shelving, ovens, sinks, etc etc), they did a wonderful job on everything....
except...
They decided to save money on tiles since they're so expensive. They purchased
outdoor tiles to finish the floors with. The texture was awful, it trapped dirt and always looked a dirty, no matter how you cleaned the floor. Major mistake.
So yeah. Research. Quality > Quantity.
Contractors are great... and they'll do a great job, but anything that you can do yourself will save big dollars! (Always feels great)
