Answer :
Keeping in mind there needs to be more context in the question I'll answer this as best as I can.
Starting off people sometimes reward themselves after reaching a goal to increase their productivity and to feel good about what they did.
- Treat yourself to a meal
A reward you could give yourself could be to let yourself eat one of your favorite foods or eat out. For example if you were on a diet this would be your one rewarding break and to make sure you don't break your routine or what you did you could limit your consumption.
- Designate a day where you will do nothing
Another reward could be to choose a day where you can do nothing so if again you were on a diet or trying to loose weight this could be your one chance to rest.
- Buy something for yourself
This reward could be something to help promote your happiness and if you want every time you reach a goal you increase the amount of money you spend on yourself. This doesn't just talk about things you buy at the store this could also
- Do something you enjoy
This reward honestly varies from person to person and you could do things like take a relaxing nap, take a bath, do an activity, or take on learning a new skill.