There are many ways to save and do so legally. I don't really like accountants like Green Trader because they tend to be very conservative at the trader's expense. I use an accountant who only handles traders and has some of the biggest players in Chicago. He has been in it for 35 yrs and knows what flies and what doesn't. I won't go into specifics because it situation dependent, but there is plenty of help from the government when it comes to trading under a business.
I don't like conserative accountants either, they have cost me too much money in the past. I'll have to study some more on incorporating for trading. Where I'm at I don't think I'll find an account who is an expert on trading so I have to learn what I can myself first.
When I said conserative accountants cost me too much in the past I meant I was paying too much in taxes. The accountant I have now is very reasonable and aggressive. I pay him about $500 a year apx. on my construction business tax returns, sometimes higher sometiimes lower depending how organized I have my stuff and how complicated the returns are.