Some applications don't open properly (such as Photoshop, which sometimes has an empty menubar) when they are the application that causes Classic to launch.
The standard way around this is either to have Classic running all the time, or to start it up first from System Preferences, which is at least a two-click process.
Instead, I launch Classic once, and when the start-up application appears in the Dock, I click on it and select "Keep in Dock." That way, I have a one-click access to it in the future. I also have a little freeware app called Classic Spy which shows the status of Classic in my menubar.
Perhaps these are not hint-worthy strategies, but they work for me.
[Editor's note: Seems like good advice to me, and I'm not sure we've ever published the "Classic icon in dock" tip. It's possible it was buried in another hint at some point in time, but the collection of tips to search through keeps getting bigger and bigger!]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020314100311446