Milling and routing have a lot in common but there are differences.
The main difference being that milling is performed on metals as a rule. They are usually consistent in their micro-structure.
With routing, it's usually timber and there there are many inconsistencies. You have a grain to start with. Other inconsistencies like knots can cause difficulty too.
Different cutters behave in different ways. Blunt cutters are dangerous. A good way of getting your hand in, as they say, is trial and error with a scrap pieces of timber the same as your workpiece. Also, rehearse your planned cut in your mind while observing where you may have difficulties getting around your workpiece. You'll avoid making too many scorch marks when you do the cut for real.
It is good to have a variety of different clamping methods on hand too. Sometimes a clamping solution will foul your router's path around the template, especially where there are complex curves. In these cases, take care to support the workpiece securely against the forces that your router is going to subject it to and make a series of cuts, re-positioning and clamping where necessary.