Use fabric and accessories to extend the life of clothes they grow out of. Kids grow so fast, sometimes so much so that it seems they barely get any wearing time from their clothes. What I like to do with my kids is have a fun craft session where we add fabric and other accessories to clothing to increase the size. For instance, if jeans still fit the waist but are a little short in the legs, add some length with fabric, lace, and other embellishments. If the waist has gotten a bit too small, open up each side seam and add some fun fabric to let the waist out a little. Add matching fabric in other areas (such as the knees) that might be worn out.
Use gentle laundry products. Frequent cleaning with products that are too harsh on clothing can reduce its lifespan. Try using gentler, non-abrasive cleansers that are free of chemicals, perfumes, and dyes. This can help increase the number of wears your child gets out of the clothing. It's also better for the environment and the health of your child. Look for products made from natural ingredients. But also check to make sure those ingredients are not too harsh on your child's clothing or to the skin.
Wash on gentle cycle or by hand. Kids are already rough on their clothes as it is. Ease up on the wear and tear by hand washing their clothing or washing it on gentle cycle. Washing clothing by hand can be much gentler than other methods if done right. Try not to scrub too hard as this will certainly not help the clothes last longer. Lukewarm water is best when it comes to being gentle with clothing. Extreme temperatures can cause colors to fade. Also, if you are washing by hand, lukewarm will be gentler on your skin.
Line dry the clothing. Rather than exposing clothing to the intense heat in a dryer, try line-drying the clothing instead. If you must use the dryer, use a low heat or air dry setting. Over time, exposure to high heat can cause fading in your child's clothing. Line drying can help make the clothing last longer. But be careful of how you do that as well. If you leave the clothing in high temperatures outside or right in the direct sunlight too long, fading also may occur.
Cut it up to make new clothing. Another thing the kids and I like to do, especially my oldest daughter, is to cut things up for making new outfits. Skirt too short? Chop a piece off of another in the same condition and sew the two together for a funky look. Have a dress that's grown too short? Chop it up to make a shirt from the top half. A bottom seam will be easy to sew. Use the leftovers to add to a skirt or chop it up to make patches, headbands, and more. The kids and I always have fun doing this. It helps us extend the life of their clothing and also gives us a great family activity. Be careful when deciding who can use scissors and other sewing materials that may pose a danger.