Practice holding the knife at a 20 degree angle. Most straight blades need to be sharpened at a 20 degree angle. To find the angle, hold the directly in front of you so it's straight up and down. This is 90 degrees. Tilt the knife halfway towards the table so it's at a 45 degree angle. Tilt the knife halfway again so it's about an inch (2.5 cm) above the table. This should be a 20 degree angle.
Our large selection of stones from many well-known manufacturers will allow connoisseurs to find the ideal stone for their needs. Because all manufacturers formulate their stones to emphasize a different mix of qualities, and because these qualities can vary widely between different stones, most woodworkers choose stones from several manufacturers to build up an optimal set of sharpening stones. Then again, once you get to know the characteristics of certain types of stone, you may find one supplier who will provide all the stones you need. Sometimes this can be an advantage. But there is no one size that fits all; each stone must fit your needs and work style.