Walk up at least one flight of stairs when going to and leaving from work. Walk up the escalator(s) (don't push non-mobile people on escalator--wait for them to get off if you want to walk up the escalator!). Grab house keys, drop off garbage, & then walk one or more blocks.
If you have a backyard, do sprints to burn off a little stress. Dance in your kitchen (or other room) while you are waiting for your meals to fully cook. You don't have to be a good dancer to bring a smile to your face and burn off some calories! Handwash your dishes. Baby steps!!