Measure and mark the length of the piece to be mitered. A good example might be the side pieces of a box that need to be mitered at the corners. Mark the face of the piece, where the long edge of the miter should be.
Raise the blade up to its full height by turning the side crank on the table saw, typically located on the right side of the saw body, under the table. Set the angle of the cut by turning the crank on the front face of your table saw until the indicator points to the correct angle on the gauge built into the wheel. Common corners are 45 degrees on each piece to form a 90 degree corner.
Release the rip fence and slide it far enough down the table to be clear of the piece you are cutting, or remove it if the piece is too long.
Insert the flat metal bar on the bottom of the miter sled into the square slot on the right of the blade with the flat “fence” in front. Double check the gauge on the miter sled to ensure it is set to 0 or 90 (depending on the sled's markings). It will be the center mark on the half circle gauge at the back of the sled. Adjust by turning the push handle counterclockwise and twisting the fence section until it is properly aligned.
Place the work piece in front of the sled with the flat edge of the work piece perpendicular to the edge being mitered flush against the front face of the fence. Align the mark you made so that the blade is against it on the left side of the mark.
Turn the saw on and allow the blade to come up to speed. Grasp the handle of the sled with your left hand and hold the board firmly down to the table and against the sled fence with your right. Push forward at an even rate, contacting the edge of the blade. Continue pushing, holding the board firmly down and against the fence until the cut is complete.
Push the work piece past the blade. Turn the saw off and allow the blade to stop spinning before retrieving the piece.
Raise the blade as previously described. Set the angle to 90 or 0 on the table saw so that the blade stands perfectly upright. Set the miter sled into the channel in the table's top. Set it to the right of the blade for miters on the left end of your work and vice versa.
Adjust the miter sled to the desired angle by turning the handle counterclockwise and twisting the fence to align the indicator with the correct angle on the gauge at the back of the sled. Turn the handle clockwise to lock it in position once it is aligned. Adjust the fence to angle with the end away from the blade, further away from you, so that the cut will be made on the trailing edge of the board. To cut the other direction, position the sled in the channel on the other side of the blade.
Measure and mark the piece to be cut so that the shortest end of the miter is marked on the front edge of the board. Align the mark with the blade. Start the saw and make the cut as outlined previously, holding the work piece down to the table and against the fence. Push past the blade and turn the saw off, allowing it to come to a stop before retrieving the piece.