Moms tend to buy clothes for their kids that reflect their own style of dressing.
Try to pick outfits for your kids that will work for their lifestyle. If they are into sports, buy accordingly. If they are girly girls, most likely they will want to wear clothes that are more frilly.
Make sure that they wear the clothes that fit as they grow up. Some kids will want to keep wearing their favorite item and will not let it go. ( like the blanket dilemma that they drag around forever ). Let them dress their favorite stuffed animal or doll with that outgrown item, and buy them something new that fits.
Find stores that carry clothes that are returnable. There is no guarentee that just because you love it they will too.
Shopping without your child in tow really is okay. Measuringupapp and/or the book version will give you the clarity to buy what they need and know it will fit.
Most of all, have fun.
Lauri Chertok, the app developer, is a mother of two who has worked in children's retail and saw a need for people to have an easier time shopping for clothes.