I've little experience creating custom themes. A company likes my other design work and wants to hire me freelance to create themes for their clients. I assume once I get going I'll speed up but would like an idea from experienced theme designers how much time on average it takes you to create a basic theme from scratch given only basic guidlines/info from the client. They want it submitted ready to plug into their custom folder (php + images). I'm grateful for any advice, pointers and idea on average time it takes most designers.