I don't take the home office deduction, but I do consider the home office to be my primary place of business, so I take mileage to the work site. Section 179 deductions are great for cellphones, laptops, and other tech used by the business. Any professional services like lawyers, accountants and exotic dancers. Temp office help.
Meals during work hours, or after-work drinks, I take these but since I own the company, I'm limited to 50% of the cost. Most of my meal expenses are with clients, so I feel pretty safe deducting these.
The rest of the expenses are traditional business expenses - supplies, insurance, air travel. I don't play games with the expenses, I keep receipts for everything $25 or more, and make sure I can document every expense I claim. I stuff all these in envelopes marked by month and year, and save these for seven years. Well, they end up sticking around more than seven, but that's the idea. Just went through our basement storage and burned receipts from the 90's... I may have to tune my recordkeeping purge criteria a bit.