Routing mating edges
When joining boards to make a wider surface, you can add some interest to the final piece by using different woods and by joining them using a wavy shape instead of a straight edge. Simply make one pattern and then use it to create a mirror image. Use an inlay bushing to ensure perfect alignment. This will account for the offset; otherwise, you would need to make two separate templates.

Routing a cavity or mortise
You can use a guide to rout a cavity or mortise using a simple template. Establish the required dimensions, draw the shape on your template and then add the offset. Cut the hole in the template and sand the edge smooth. Attach the template to your stock and, using a plunge router, position the guide in the hole. Plunge the bit into the stock and carefully rout out the waste. Use an up-cut spiral straight bit and rout the waste in several steps.

Boring holes
Repeatedly drilling a regularly spaced pattern using a drill or drill press can be tedious, as you have to measure and mark every hole. Instead, measure and mark once onto a template. Mark the location of the holes and bore them using a drill that matches the exact outside diameter of the appropriately sized guide. When all of these holes have been drilled, mount a cutter into the router that matches the hole size required in the workpiece. Attach the template to the stock, position the guide in a hole and plunge to bore the hole. Repeat the process on each hole.

Creating inlays
Inlays can add an attractive element to your work, and using a guide makes the process easy. Create your pattern as described previously and rout the inlay recess with the inlay bushing installed on the guide. Then, remove the bushing and rout the inlay using the same template. The bushing automatically accounts for the offset when routing the recess and the inlay, allowing you to use a single template to cut a perfectly fitting inlay.