I'm a stay-at-home dad of 3. These are the products and services that help me save money.

• My wife had twins in March 2020, and shortly after, we went from two salaries to one.
• I had to get creative to save money with three kids under 3 at home.

Hacks, DIY projects, and saving money are a few of my favorite things. I've always enjoyed saving a buck, and when our family of three added twins only days before lockdowns began in March 2020, it was clear that we were going to have to get creative.

In addition to almost doubling the size of our family in a day, we also went from two salaries to one when we made the difficult decision to move our family and for me to stay home to take care of the kids full time.

As a stay-at-home dad to three small children — one of whom is now 5 years old, with the other two both being 3 — I've spent the better part of the last five years doing my best to hack fatherhood. If there's a product, trick, or recommendation out there for kids under 5, the chances are that I've tried it.

Here are six of my favorite parenting money savers for kids from birth through early childhood.

A pitcher to mix formula so you don't waste any

When our first son started drinking formula, we mixed each individual bottle. We learned quickly that mixing in the bottle isn't great since it's hard to get rid of clumps and it creates bubbles that then turn into gas once the baby drinks the formula. And worse, once a baby's lips touch the nipple, the bottle is tainted, and you can't just pop it back in the fridge to use later.

When we had our twins two years later, we found that using this formula pitcher was a game changer. We could mix a whole day's worth of formula and keep it in the fridge — it's good for 24 hours if it hasn't been sipped. Then we would portion out whatever small amounts we needed for feedings.

We spent way less time preparing bottles and wasted much less formula too, and that stuff is expensive.

A diaper subscription to save money and time

All of our children are now, thankfully, out of diapers, and I don't wish to fathom how many I changed in total during my four years of diaper madness. Diapers are expensive, they take up a ton of space, and they're a pain to shop for and bring home. Diaper subscriptions take some of the pain out of this dirty little corner of parenting.

A subscription ensures that you always have diapers on hand. You don't have to cart them around a store or pack them into your car, and subscribing can save you a substantial amount of money as well. Subscriptions are now available for many diaper brands, so you can find the one that fits your baby and your family best.

We love hand-me-downs

In a world already littered with our trash, and with landfills filling up ever more rapidly with fast-fashion discards and plastic-toy rejects, it seems crazy to buy your kids new clothes that will only fit for a brief period and toys they will love for even less time.

We've enjoyed dressing our children in mostly pre-owned clothes since they were newborns, and we love pre-owned toys just as much.

My wife is part of our local "Buy Nothing" group on Facebook, where like-minded people will post items that their kids have outgrown, and all you have to do is claim them and pick them up. The key is also not to forget to pay it forward when your kids have outgrown the things you claimed.

Our kids wear mostly pre-owned clothes

Besides hand-me-downs, one option we have loved has been the Swoondle Society, which takes all the headache out of reselling your kids' clothes once they've outgrown them.

Swoondle sends you a postmarked bag to fill with clothes and drop off at the post office. Once received, Swoondle will go through your submissions, and in exchange, you receive credits to use on pre-owned clothes for your children in their next size. Not only does it make the process easy, but shopping for new clothes with your credits is a lot of fun, and they have a great selection of stuff.

Goodwill, the Salvation Army, and local consignment shops are other great options. Perhaps better than any of the stuff you will give your children from these outlets is the impact on the environment that we'll leave behind for them. Any toy or garment we keep out of a landfill to be used by another child is a win.

Toys that grow with them

Kids grow up fast, and this year's bike or scooter will likely be collecting dust by next year unless you find an option that grows with your child. We had our kids on Micro Mini scooters before they were 2 and found that the available seat and push bar allowed them to get comfortable on a scooter long before they could actually ride one effectively.

The push bar allowed us to control where they were going, which was especially helpful when navigating busy city streets with them. Once they could scoot on their own, we took the seat off, and now they can use the same scooters until they're 5.

We've loved the Liki Trike from Doona for many of the same reasons, and there are also balance bikes that convert to pedal bikes to make sure your kids keep on moving and don't get bored.

Memberships are key

There are many memberships out there that can pay dividends if you have kids. One of the biggest for our family is our warehouse-club membership. Our kids go through the snacks and foods that they love at a rapid pace, and the savings we get from buying them in bulk adds up. The cost of the membership pays itself off in no time, and over the course of a year, the savings are significant, particularly when the club adds savings for gas, which is another big perk.

Our kids have also really enjoyed our memberships to the local children's museum and art museum, and we've enjoyed not paying for tickets every time we go.

The best membership, hands down, has got to be the local library. Our kids absolutely love going to the library. They stock up on books, read, enjoy time at the craft table, and take part in story time and sing-alongs with other kids. That's wholesome fun, and the best part is that it's 100% free.