Listen to Jodi explain this at 43 minutes into the show podcast below:

According to Business Insider
How much to tip varies by service but is generally 18% of your bill.

 

“You can also consider creating an entirely separate category within your budget only for tipping. This means that if your tipping category runs low, you can decide how to dine out based around the tipping amount.” When in doubt, always tip at least a little something.
Uber/Lyft
$1 to $2 per person for shorter rides; 10% (up to 20% for exceptional service)
Tip at the end of the ride, and tip extra for traffic, construction, distance, inconveniences, and if the driver helps with luggage or packages.
Waitstaff

15% (up to 20% for exceptional service)

Package Delivery

$5 (up to $10 for exceptional service)

Tipping here should be considered as an extra gift for those hauling heavy packages to your door. If they had to climb several stairs or it’s extremely hot, consider tipping more.

Movers

$5 (up to $10 for exceptional service)

Tipping here should be considered as an extra gift for those hauling heavy packages to your door. If they had to climb several stairs or it’s extremely hot, consider tipping more.

Haircuts

10% to 15% (up to 15% to 20% for exceptional service)

Tip after the service is completed, and tip everyone involved. For example, different people washing and drying your hair should receive $5. The person doing most of the work should receive the biggest tip.

Food Delivery

$10% or $2 minimum

Tip when paying online or when the food is delivered.

Concierge

$5 (up to $20 for exceptional service)

Tip when you receive the service. Tip little or nothing at all if the concierge only provides directions.

See more at Murphy, Sam & Jody.