If your woodworking plans call for only one or two mortise and tenon joints, you can probably get away with creating the mortises with a power drill and a sharp chisel.
But what if your woodworking project calls for a number of mortise and tenon joints? Typically, you might turn to a dedicated, hollow-chisel mortiser, with which you could crank out a number of clean mortises in a hurry.
If you don't have space (or the budget) for another power tool, but have a drill press, there is another option. Most floor-standing drill presses can accommodate a hollow-chisel mortising attachment. This attachment will connect to your drill press in just a few minutes, and allows you to use hollow-chisel mortising bits in sizes from 1/4" to 3/4" in width.
These mortising attachments also typically include a stock hold-down, which connects to your drill press table. This hold-down will hold your stock firm when the square chisel is withdrawn from the stock. Using this attachment makes cutting mortises safer and quicker, so resist the urge to cut your mortises without it.