Finding a Reputable Contractor
Do your research, get references and verify they they are licensed and insured or bonded. take time to go and check out some of there recent projects, and speak to the clients if possible. Doing this could save you from future headaches and the possibility of either not getting the job finished or having to re-due the entire project.
the Entire Amount up-front
Paying up to 1/2 down isn’t totally out of the question if you have done your homework, but you need to have some leverage to make sure the project is done in a timely manor and done to your satisfaction.;
Get a formal bid
Make sure you read and understand any contract or proposal before committing to have any work started, make sure that your interests are protected, and that there is a good warranty and the terms are understood, Keep records available in case of warranty issues.