I have a spreadsheet I use. Each shop is on one line:
The columns:
MSC
Brief description of shop i.e., McDonalds, 67th ave, or Sprouts, Prescott
Date
Fee
Bonus/travel amount
"useful" reimbursement -- the value to me of something I will be reimbursed for. I might get $7 for a burger, but it's only worth $2 to me to replace a meal at home
Reimbursed amount
Total owed to me by the MSC, which is Fee plus Bonus plus Reimbursed amount
Miles driven
after I am paid, I copy the information to another set of columns on the same line, adding columns for:
Date paid
method (check, paypal, direct deposit)
time to get paid (which is computed by subtracting Date paid from Shop date)
Each column is totaled.
At tax time, I use the totals for Reimbursement and Miles driven to compute my deductions. My income is the total of "Total owed to me by the MSC" from the second set of columns (which should equal the amount they paid).
Reason: The income and deductions are taken or claimed in the year the money changed hands. So what you paid out and your mileage are deducted in 2014 but you only claim the income you got in 2014, which may include some that were unpaid at the end of 2013 -- shops where you already deducted the related expenses. Any income earned but not received in 2014 will roll into 2015 and be reported there. But you will have already deducted the expenses.
Why don't you claim the income and expenses in the year you did the shop? Because the tax law says you don't have to declare income until you receive it -- and you may not know if you're getting paid for some shops until three months after you did them. You still get to deduct your expenses, even if you never get paid. your receipt dates and mileage log needs to match the year of your tax return. So deducting miles you drove in November and meal receipts from December from the following year's tax return will cause problems if you are audited. (Unless you're an accrual-basis taxpayer, and if you are, you don't need tax advice from the forum)
FYI I have been a tax preparer for nearly 20 years. And I strongly urge you to discuss your tax strategies with your own tax professional. The above information is about record-keeping and what the tax law allows; how you fill out your tax return should be determined based on your own tax situation.
Time to build a bigger bridge.