Around my third song I stumbled on a method to make guitar patches sound more vibrant. To the right, you will find a small excerpt from my track "Stunt Driver", with and without this effect. See if you can spot the difference in these examples.
As you might notice, the top version sounds quite stale. All notes seem to have the same drone to it. When you play the bottom version, the riff somehow comes to life. This is because the frequency of the notes changes. This can be done with the 'Scream 4 Sound Destruction Unit' that comes with Reason. You can download the patch I used in the above riff and for my 7th track.
When you open this patch in Reason (load instrument), turn the P1 knob (tone) to around 14. Now, while pressing a key on your keyboard (you should now hear a guitar sound), slowly turn knob P2 (frequency) up and down. This will make the frequency of the note you just hit swerve up and down. You can even exaggerate the effect by turning the 'Reso' knob all the way up and then start using the P2 knob. You can make the note squeal by turning the P1 knob way up.
You can record this stuff live, while you play as well. Right-click on the knob you want to record (for instance P2) and select 'edit automation', in the menu that pops up. That knob should now have a green box around it. If you've sequenced your song allready onto the notebars, just press 'record' and fiddle with that knob to record your frequency shifting.
Teach me more using Reason 7!