Well, I just recently started college, and I brought some loose leaf tea but, not a tea infuser, soooo, time to improvise.
As well as my tea I had some starbucks teabags, which are (or at least were, these are from last christmas) made of plastic mesh. I used one of these teabags once and I decided that throwing it away would be a waste, so I made my own reusable teabag. Here's how I did it so you can too
I suggest using the teabag at least once before doing this.
If you want, take off the tag and the string, but this leaves a small hole. It's pretty small so tea won't really go through, but if it bothers you, just sew it up.
First of all look at the teabag and find the folded side, on three of the sides the mesh is melted together, and on one it's folded. So, tug gently at the seam opposite the folded side until it separates and keep tugging until the top is totally open.
Then thread a needle and sew along each side of the teabag (in the picture you can see). On one side leave the strings loose and tie the ends, so its a little drawstring pouch.
Pour out the used tea inside and pour in about a teaspoon of your own, pull the bag closed and steep away!
Hope this is useful!!