The most common problem about bike commuting is a flat tire. I just don't know why but it always happen to me. At one time I was replacing 2-3 tubes per week. Whoaa...it's really costly as per tube it cost me RM10...sometimes RM16. So I began to learn on how to patch a tube. A box that has 48 patches inclusive of glue only cost me RM10. So per patch it's only 20 sen. Another thing that you need is the sand paper.
Step 1. Rub and clean tube repair area using the sand paper (make sure the rubbed area is bigger than patch)
Step 2. Apply glue to repair area and allow to dry (Ensure coated area bigger than patch)
Step 3. When the glue is dry, remove foil of patch and stitch down repair area. (When the foil is taken off, don't touch the back of patch with fingers)
Step 4. Pressed hard (I used the pump) on the patch and let it sticks fast.
That's all and it's really a simple process. I will normally do it when I am relaxing at home:-) I know someone that has 18 patches on his tube!