You can put together all of the clothes in your house that you don't use anymore, and make sure that they are in good condition (if you think they are too old and worn out, they probably are). You can even buy more if you would like, if you don't have any old clothes in good condition. You can donate to a donation center near you. Some good places are Deseret Industries or Tabitha's Way. You can also look up more on the internet for centers near you. In a short time period, it may not seem to do much good, but in the long run, it will certainly make a difference (seems like everyone donates and your contribution is small, but when it gets to someone in need, they will be grateful and happy that someone donated clothes to them).