Amen on getting 1/2 the total cost up front. I usually charge 4x the material cost. That breaks down to 25% material, 25% overhead ( shops and tools are not cheap), 25% supplies ( sand paper and finishing supplies can eat up alot of cost), and 25% labor. If the customer needs it quickly than you usually add a "Rush" charge. I have been doing this for 8 years on my own and before worked for a custom cabinet shop in wake forest. I price out the same way that my old boss does. It keeps you from working for free. When I started my buisness I was making less than minimum wage because of low bidding on jobs. Good luck with your buisness, custom woodworkers are dying out because of the prefab guys.
For furniture making, 4X materials may not be a good formula - But I'll tell you, for cabinetry, it seems to really nail it. For the longest time, I lauged at the 4x materials charge - But then I started going thorough old bids, as well as pricing surveys from Cabinet Maker magazine, and also from some of the winning bids by my competitors were getting (And maybe even doing my own secret shopping - Shhh....) I did an averave, and I'll be darned if it didn't come up to a ratio of 3.9671:1.
I price out cabinetry 3 different ways now: Excell spreadsheet; 4 x materials; and Per Box - They all come out close to one another, and It leaves me knowing I priced the job right, whether I get the go ahead or not.
For furniture, it always helps if you've made the piece before, and can track your labor that way. Keep notes on times, so you can take line items, and apply them to future projects - For example, I know that to edge band 1 component of a cabinet, it takes me approx 2 minutes - That's an average which accounts for set up, tear down, etc... So if I have a cabinet with 12 pieces to edge band, I can factor in 24 minutes of labor. A mortise may take 3 minutes. Planing 1 board foot takes.... And so on....
Start looking at what other folks are getting for their work too - Be sure to compare apples to apples, not oranges. For example, I don't comapre my prices to Stickley's. Anyone reading this who has seen my work, and the current stickley work will understand. Conversley, I know I don't have the Reputation or renown of a Kevin Rodel, or Thos Moser (yet).
And don't fall into the trap of lowering prices to sell more. Case in point, if I told you I have a Festool track saw package for sale for $100, would your first response be "I'll Take it!" or would it be "uh, What's wrong with it?"
I hope this helps
-gp