Working as a waiter in food service industry the acceptable tip is generally 20% when out to eat. However I fully understand that not everyone can afford that, and as long as people leave 10% I'm cool with that. I'm sorry but if you're out eating and can't afford to leave 10% than do us a favor and stay home. It's a complete waste of our time at work. The average server at a resturant unless we're working an upscale place is under 3 an hour on the clock +tips. The only thing worse is paying your bill, Than sitting there the rest of the night taking up one of my tables costing me money in the process. Realize most of us are generally college aged kids, relying fully on your tips to survive day to day, pay for rent, pay back loans,bills etc etc.
If I go out I'm tipping 20% of my food bill. If I'm just out drinking than I tip a dollar per beer, or 15-20 % of the final bill.
Delivery depending on the order only 5-10 dollars
Pickup unless it's curbside pickup I don't tip. Other than the kitchen no one really doing any work other than ringing in your order.