Share and give your own belongings! Donate clothes, linens, and even housewares to people who have lost their homes. Think about small kids, teenagers, the elderly, and pets, too. Find out what's in greatest need in your area and donate what you can, with one very important caveat: be sure to follow all instructions on where to take the donations, so as not to hinder any relief efforts on the ground.
Get your friends and neighbors involved to make an even larger donation, and designate one or two people to make the appropriate drop-off, closely heeding officials' instructions. If you can't give things, donate money or gift cards to grocery stores through a reputable charity.
The American Red Cross in your area will have up-to-date information on clothing, item, and food donations, as will local news affiliates. To help the thousands of people affected by wildfires in Texas, check out this page of volunteer information at the Statesman.