From my experience living in a tiny apartment with coin operated laundry and a small child:
Get rid of clutter. Throw it out, donate, or sell it.
Crock-Pot meals. Two cans of beans, two cans of rotel tomatoes, taco seasoning, and 2-3 chicken breasts can last us three meals with some tortillas or rice and some cheese.
Eat salad before meals and eat slowly to fill up faster.
Buy generic or on sale at the grocery store. We can't stock up because have no storage space, but we keep costs down.
Cloth diapers didn't work out for us because of allergic reactions, so we buy generic at 1/3 the price of Pampers. We did use cloth wipes while trying the cloth diapers. I cut up some old t-shirts to make them.
Go over your dental and vision benefits to make sure the cost is worth it. Also, I wear glasses partially because they're cheaper than contacts.
Buy good quality clothes and take care of them instead of cheap clothes that quickly wear out. Wash cold and line dry, especially the nicer items. I was able to use a few classic dresses for almost a decade, while a cheap nightgown got worn and pilled after a month.
Wash your own work shirts instead of sending them to the dry cleaners.
Use grocery bags for garbage bags. Reuse boxes for mailing or storage.
The library is good for books and also for free activities. I take my six month old there every week. You can even borrow ebooks.
If you get the urge to start a new hobby or buy something, wait at least a month. Never buy something out of enthusiasm.
If you have time, make your own bread and baked goods. Especially if you can buy bulk flour. Just don't eat all the bread right away! Plus, it's very satisfying and enjoyable.
Know your temptations. I've never seen the point of window shopping and will end up buying something if I go walk along our main street area, so I only go for a special treat or if I need to go to one of the stores. If I just need to walk, it's better to go to a park or walk around my neighborhood.