Replacement grips can be used to avoid racquet slipping. You can get a grip with tacky surface and which absorbs moisture. However, this is an expensive procedure. Remember that replacement grips should be pulled tighter and tacked down in each end. This can even be done with help from a staple gun.
Overwraps are also types of grip. You can also get overwraps of tawdry surface and ones which absorb moisture. These are less expensive then the replacement grips. You can get packs which have around three Overwraps. Apply these over wraps after every few games as fresh over grips are great for avoiding slips. You can consult a stringer when installing over wraps.
Wristbands are one of the most effective ways of preventing sweat reaching hands. As a result, your hands won’t become slippery and you can hold the racquet firmly. These are not only fashion statements but have many uses. When applied in proper ways, wristbands will prevent slipping of racquets.
You need to get a wristband which fits properly around your wrist. This will help keep moisture away from the racquet's handle and eventually stop slipping of racquet and increasing its lifespan. With dry hands you can fire powerful shots. In case the handle of racquet is most then a player tends to make a harder grip. This may even lead to blisters on hand. If a player has a habit of switching hands during a tennis game, wristbands help keeping moisture away and thus preventing the racquet from slipping.
Rosin bag or similar product
Rosin bag or similar commercial products are used for better handle grips of a tennis racquet. It is kind of a powder which is sprinkled over the handle after a game or changeovers. These are easily available in sports shops or tennis stores. The Croatian legend, Ivan Lendl, carried sawdust for this purpose.
Apply dry towel after every game. This will wipe away your sweat and thus prevent slipping of your racquet.