1. Use 32-bit color mode.
2. If you're exporting to mobile, you should probably avoid any plugins at all (but modules are fine).
3. If you're putting code in repeatedly_execute, there's probably a better way.
4. If something is fiddly or time-consuming in the AGS editor, ask! There might be a shortcut somewhere, or a simple improvement that can be made.
For coding, there was a thread recently with some tips:
http://www.adventuregamestudio.co.uk/forums/index.php?topic=55575.0It's hard to say what modules are worth using, since it depends completely on what you're trying to do. The
Tween module gets a lot of use, the various UI modules that come with the templates save you a lot of work if you're using any of the common UIs (and particularly the LucasArts/Thimbleweed Park UI is quite complex to build in AGS), I always use the
MultiTextBox module for GUIs (so you can have different text boxes on one GUI and type only in one of them), or you could use my
TextField module. The
Timer module is better than built-in Timers.
If you're making your game with voice, then the
Speech Center editor plugin is a must-have. The
Dialog Designer can also be a useful tool to write branching dialog.
Those should be some of the most relevant general-purpose ones.
Welcome to AGS!