The more money you save, the more you can put into your project.
Working with a professional architect or designer will save you in the long run because they’ll know all the best options for your situation. Plan thoroughly. Don’t make changes once the products are ordered.
Be flexible. For example, if you can’t afford to do the whole bathroom in hand-painted tile, use a few as accents instead. Try to avoid moving existing pipes, at least not more than 6 inches.
Do a little of the grunt work on your own. If you have a truck, see if you can dispose of all the trash yourself, saving the dumpster costs. You can save more by tearing out your old bathtub ahead of time.
You might also try tackling the painting and papering.