Sometimes, you might have a requirement that can’t be met using standard page layouts and you need to turn to Visualforce. But, maybe only a subset of the records need to use a Visualforce page and you’d prefer the others to stay using standard page layouts. The solution here is to use a Visualforce dispatcher page that redirects the user to the correct page depending on the criteria you set. There are several good posts about using a dispatcher page to redirect the user to different pages depending on specific criteria, including a classic from Jeff Douglas.
I haven’t seen a post that covers how to handle passing parameters from one page to the next. For example, if you are creating a child record from a related list, the new page prefills in the parent record values through the use of URL parameters. If you have a dispatcher page redirecting users, then the parameters can get dropped and your users don’t have as smooth of an entry process. Here’s a way to redirect and keep all the parameters. I ran into a few oddities when implementing this. Hopefully the code below helps.