1. Research material, fixtures & appliance costs early in the process. You can decide then where to save and where to splurge. This also prevents change orders with contractors which can increase your budget and delay the project.
2. Doing some of your own demo that can save labor costs.
3. Clean up at end of day so you don't pay contractor to sweep up.
4. Look at Salvage/Humanity ReStore for vintage, recycled or lightly used materials. You may be able to find exactly what you're looking for, for a much cheaper price!
5. Check to see if it makes since to reface or paint cabinets rather that replace, if they are in good condition. You may even be able to buy new doors keeping the boxes.
6. Make a plan that does not include moving plumbing fixture locations if you can.
7. Installing a single ceiling fixture or wall light fixtures instead of recessed lighting can save you a lot of money.
8. To avoid eating out during a kitchen renovation, set up a makeshift kitchen; microwave, coffee maker & refrigerator etc.