Nothing from tax refunds. I try to break even so I don't have to pay or receive a refund. I've already been taxed on my income, I don't want to be double taxed by getting a refund.
I too use side money to fund my hobby, but now that the government is stealing more of our money ( new tax increases), my photography will take a hit.
I do the same, I try to juggle my W4 entries throughout the year, when I'm working W2 jobs (rather than 1009 contracting which I'd MUCH rather do)...so that in the end, I either only get back $100 or I pay $100 in taxes.
I see no reason to give the govt a tax free loan throughout the year, just so they can waste that too.
One thing I'd suggest....incorporate yourself, and that way...you can make all those photography purchases tax deductions.
Make it work for you, rather than have the tax man take your 'toy' money.