Get Multiple Bids from Licensed Contractors. Remember that you’re the shopper here, so don’t settle for just one bid. Check with the Contractors State License Board to make sure each contractor’s license is active and in good standings.
Get It In Writing. Since a written contract protects you and the contractor, all agreements should be put in writing.
Specific Contracts are golden. Make sure the contract includes everything that has been agreed to, up to and including complete cleanup and removal of debris and materials, along with special request like saving lumber for firewood or saving certain materials or appliances.
Get a copy. Once you sign , both you and the contract are bound by everything set down in the contract. Make sure to get a copy of the contract. Make sure to get a copy of the contract and keep it for your records.
Check the financial terms. The contract should include the total price, when payments will be made, and whether there is a cancellation penalty. You should expect to make a down payment on any home improvement job. That down payment should never exceed 10% of the contract price or $1,000, whichever is less.
Source: Contractors State License Board (CSLB)