I was a self-employed contract mechanic for 6 years with no employees. In Texas it is very easy to set up an LLC and I did it myself online to try to remove some personal liability. In doing so, my personal taxes and business taxes are one in the same, so my CPA told me so I didn't need to put myself on the payroll. I could have one bank account for everything and at the end of the year just write off what was a business expense. That makes it easy, but I would suggest having two accounts and transfer funds for all personal expenses and then at the end of the year, if you don't have a receipt for something, you can use your bank statements for your write off record.
I am no CPA, but I definitely believe a good one is worth every penny you pay them. As far as what to write off, I agree with pretty much everything that was stated.
On the liability side of things, I had $500,000 in liability insurance also, which is a tax write off. It only cost me as a mechanic around $1000 a year. Some of my customers required it, and since I often worked inside other peoples shops I figured if I started a fire and burned the place to the ground it would be better than paying out of pocket. As far as equipment went, my service truck and tools were mine personally, but I "leased" them to the company which was a tax write off. Then, if I was sued, the company had no assets to speak of and there was nothing to go after. I also had Workers Comp on myself, even though I was not required to because I had no employees. I did this just to give me a little more health coverage in case I was hurt or in a car wreck while "on the clock"
Don't take anything I have said as law, check it all out for yourself, but this is what I did and it worked for me. I am no longer self-employed, but will be again someday I am sure. For now, it is better for my marriage to bring home a steady paycheck and at the end of the day, I am almost making the same and have benefits to boot.