I think that one of the main problems with rackets is that more often than not, the grip doesn't quite feel right in your hand. This could be because of the shape, the bevels being too sharp or too round, not being quite the right size. On all of my rackets, I've customized the grip to some degree, even drastically. One thing I've noticed is that the grip shape that feels the best for one racket is different from another, so is related to racket design. So you need to *play* with a racket first to evaluate what needs to be changed in the grip versus just holding it. I'm totally against heat shrink sleeves because of the substantial weight (0.5oz) will totally throw off the balance of the racket. If the grip feels a bit too large with the original grip, just substituting with a thinner synthetic grip will often do the trick. If the grip feels too small, the methods to use are a synthetic grip and electrical tape since this will minimize gain in weight. For bevels that are too sharp, I remove the original grip and round off the bevels with sandpaper. Caution is required that you don't sand off too much of the bevels otherwise the grip can become round in a hurry. I rounded off the bevels on my RDXmid and IPrestige mid because they were too sharp. Another problem are grips that are too round or rectangular (Head). The way to solve this is to apply horizontal strips of electrical tape along the bevels to make the shape less or more rectangular. This works well and adds very little weight. I often find grips to be too bulky in the upper portion of the handle so I sandpaper the upper portion uniformly. This also seems to improve improve maneuverability significantly although I'm not sure why (?) So just about all grip problems can be fixed with nothing more than electrical tape, overgrips, scissors, sandpaper, and a good eye. Now if you're trying to increase the size from 1/4 to 5/8 or decrease from 5/8 to 1/4, then it's almost impossible to do without seriously affecting the weight and balance of the racket. Also, you're quite likely to botch the job of sandpapering when you're removing that much material.