I'm so excited that many of my non-sewing friends have decided to give it a go since seeing some of my clothes hacks. It's a good idea to start by making simple changes to clothing to get an understanding of basic sewing techniques. The last thing you want to do is dive into really intricate, complicated sewing projects, get discouraged, and quit sewing for life! Here is a super easy tutorial on adjusting an elastic waistband. At some point or another this will come in really handy for you.
Step 1. The rippin' and the tearin'
Use a seam ripper to get underneath one of the stitches. The curved part of the seam ripper (between the tip and the red ball) is actually a razor and will cut the thread for you. Once you cut that first thread you should be able to lift each stitch one at a time and slowly pull it out. If you don't have a seam ripper you can use a dull fork to lift the first stitch, then snip it with a pair of scissors, then use the fork to pull out the remaining stitches :)
Step 2. Size it Up
Step 3. Sew the band
Step 4. Cut the Remaining Elastic
Step 5. Close it up
So there it is. Keep in mind that this same technique can be used for replacing an elastic band that has worn out on the favorite skirt! Just remove the old elastic band, slide a new one through the channel (use a safety pin to help you feed it through) and finish up as shown!