Because I use a laptop for navigation with almost limitless capacity for storage I have kept the waypoints, routes and tracks of EVERY voyage I have made in the last 15 years or so. I flash the routes up time and again and re-use them. It is a great comfort to know each one is a safe route with no hazards such as buoys, sandbars, headlands or rocks in the way.
Also I have named and kept every waypoint I used on each route so now it is a simple matter to make new routes in the sure knowledge that every waypoint really is where I want it to be and in sufficiently deep water at all states of tide. I have over 800 of them and when constructing a new route I simply pick the ones I need. They can be made to appear on the chart and are also viewable as a table sorted alphabetically or by Latitude or by Longitude.
In fact people say my boat knows where to go to such an extent that I hardly need to be aboard!