While raising my two boys we lived below poverty level for nearly a decade.
I didn't have enough money to include clothing in my budget, and any clothing we did buy had to be squeezed from another category, for example, the already bare bones groceries category.
I learned early on that boys are harder on clothes than girls.
I didn't have daughters to make that direct comparison, but was not hard on my clothes as a child, and neither were my sisters.
We passed our clothes down to six girls, and some dresses were still in wonderful condition on down to the sixth girl.
It became evident early on in my life as a mother of boys that I needed to secure high quality clothing somehow, even though I couldn't afford it.
Here are the tips I learned by trial and error:

1. Resist buying brand new clothing from cheap retailers.
   More than once I would feel burned having bought brand new clothing.
   I found that seams began to rip out after several washings, and hems began to unravel.
   Thankfully I was handy with a needle and thread!Not to mention the material would easily rip and tear, and the colors would run and fade.
   The only bad thing when resisting the urge to buy brand new was my boys longed for the popular cartoon characters on their clothing and these could be hard to find on a whim at the thrift store.
   
2. Shop at thrift stores in affluent neighborhoods.
   I found when shopping in the more affluent areas of town that not only were the prices lower, but the quality of clothing higher.
   When shopping at thrift stores in my part of town, where most were living at poverty level there was less of a selection, the clothes were from the cheap retailers and much more likely to be worn out.
   It seemed to me that the parents living in the more affluent neighborhoods could afford to both buy from the expensive retailers, and they could buy more clothing for their children.
   Children can only wear an item so many times until they grow out of it, and the clothing would be donated to the local thrift store.
   In this way I often found high quality brand name nearly new clothing for my children.
   I suspected that the more affluent parents were more likely to have the expected "2.
   5 children", and were less likely to "hand down" clothing.
   Another aspect I considered: affluent parents were less likely to have the tendency to hoard clothing since they were able to buy brand new every season.
   
3. Shop out of season.
   This is my favorite tip.
   When you think ahead to the next season, there is a much larger selection.
   Living in our mild climate we didn't need a lot of heavy clothing, so during the winter I put my boys in sweat pants and sweat shirts.
   I'd stop at the thrift store about one month into summer and pick up several pairs of pants and tops in the next larger size, all in fantastic, nearly new condition.
   And vice versa for summer wear, I'd stop by the thrift store during the winter and pick out several pairs of swim trunks, shorts and tops.
   I also shopped this way for myself.
   I'd pick out an article or two each time we shopped and always had something cute to wear when out and about.
   
4. Shop with the future in mind.
   More and more schools have a dress code.
   Keep that in mind as you shop.
   Are your children entering school in a few months? Is your sister getting married and your child will be in or attend the wedding? Keep your eye out as you shop.
   
5. Buy dark clothing rather than light, and prints rather than solids.
   Dark clothing or clothing with prints are much more forgiving of stains than white or light clothing.
   For several years I never bought anything that was light colored which made laundry chores much easier.
   

I hope you find this article helpful for buying clothing for your children.
Whether you are living at poverty level, rich or somewhere in between, I know you'll find these are great tips for dressing your children nicely.