I do not know what machine you have but the 1/4 foot is very easy to use. You can practice on scraps to get the right setting. First test with a scrap with the needle in the default center position. Place a scrap under the pressure foot and align the edge of the fabric with the guide on the foot and sew serveral inches, remove the scrap and measure the distance to the edge of the fabric from the sewn line. If it is not a 1/4 inch then adjust the needle position position and test again until you get the correct setting. Depending on which model machine you have the needle positions can be moved in .10mm increments. If the machine does not have small increments between needle positions then talk to your dealer to see if it can be adjusted. Again it all depends on the machine.
Janome MC6600, Bernina 240, Juki MO735 serger, 1948 221-1, 1951 201-2