For occasional special characters, if you are using a Microsoft installation, you might try the character applet which gives you access to the complete character set for each font installed .. eg on my installation this is at
Windows\System32\charmap.exe
ie including all the non-keyboard characters ...
I have used the program on each Windows version and the filename has always been charmap so it ought not to be too difficult to find on any installation.
If you know the key combinations, characters can be entered directly but charmap is great for lazier folks like me.