Don’t eat chicken/beef etc most of the time – save it for shabbos and yom tov. Eat more eggs, beans, rice, potatoes and vegetables.
Walk everywhere you can. Bike further distances.
If you just got married, I am assuming that you each came with an adequate wardrobe. Don’t buy new clothing unless absolutely necessary.
Don’t hire out cleaning help. If you find that you and your wife are having trouble keeping up on your current schedule, take off 1 hour a week from Kollel. That should be enough to clean your apartment since you don’t have kids (again, going with the newly married just in Kollel vibe). If it saves you the $100/week, its that much longer that you can stay in Kollel.
Check out http://www.pennilessparenting.com to see how a frum womanlives frugally. Its a kosher site – and all the recipes are kosher:-)
Get rid of smartphones – use pay as you go phones and rarely use them.