I have unconventional methods of doing things and I'm not afraid of sharing them. Case in point below. To cut the drawer divider rail slots for the Shaker chest I'm building I defaulted to a method I used for a highboy and a serpentine front chest. Shop Shots of both pieces are in the shop shots section back in 2001 or 2002. I first machined 3/4 slots (for the router guide bushing) in a piece of 3/8 x 3" aluminum that is the same width as the chest. 18" or thereabouts. I added counter bored holes to the guide to screw it to the case sides during the cutting operation. Location is tedious. You had best measure twice, know how to add fractions and have a long accurate scale. Other than those issues it works very well.
I use two routers. One with a 3/8" straight bit for roughing the other with a 5/8 dovetail bit. Mark the front of the router front and make sure you keep the front facing the correct direction (bushing to bit center error is eliminated)