If you want to convert a hip belt to a waist belt or need more holes for a better fit, a hole punch tool, pencil and ruler is all you need.
I bought my tool from Ebay for £3.75 including shipping. You can also use it to punch holes in wristbands too.
Measure and mark where the new holes should be on the underside of the belt. Press with a slightly blunt pencil to leave an impression. That way there will be no permanent markings.
Select a hole size to match the existing holes. Carefully position the punch in line with a marking and squeeze until you hear a snap. You may need to twist the belt a little to ensure a clean cut. Release and presto, you have a new notch on your belt!
I've converted my thin hipster belts to waist belts. Since they are extra long on the end, they can be worn looped around as shown below.
My shoe repair shop charges £1 to punch two holes. With my hole punching tool, it's faster, easier and cheaper to DIY.