I'm no expert, but here's what I've learned from reading around and asking lots of questions...
For auto-attacks, it's all about the
timing and ACT can help a lot. You can configure a trigger to notify you when your autoattack fires. Credit goes to Dantel for that link - it's a how-to on setting up ACT to notify you when your auto-attack lands. You can also set up triggers for when you miss, when you crit, when you're too far away, etc...
As far as tips to increase DPS, learn, live and love the following...
1) The /weapon command will show you the current delay on your weapons. This can change with haste gear or buffs from your skills or someone else's spells. This will give you a ballpark idea of how often your auto-attack will fire.
2) There's no CA that can't help you. Practically every one is useful and I can't think of any off the top of my head that should go untouched, but some things are situational. I'm hesitant to use Compromising Thrust if I'm soloing, but if a mob is close to dead, other CAs are down and my auto-attack just fired, I'll go ahead and use it. As far as using a CA that does less damage than your auto-attack, if it has some added bonus like debuffing or something that will compliment your other CAs, then use it when you can. If all your other CAs are down and your auto-attack just fired, then why not use it? You're going to have to wait for your auto-attack to fire again, anyway. If you can nuke a Hot Pocket in 1.5 - 3.5 seconds, then go for it. But if not, then throw whatever else you can before the next auto-attack goes off.
3) EQUALITY! If you're going to be timing your auto-attacks, with or without ACT, make sure your weapons have the same delay on them. Unless you're some kind of savant with timing and math, learning when to pause for auto-attack with two weapons of different delays is going to drive you insane pretty quickly. The difference of .5 seconds seems minimal, but it makes a difference. Weapon A will fire at 3.5 seconds and Weapon B will fire at 3.0. Then Weapon A will fire at 7 seconds and Weapon B at 6. Then A at 10.5 and B at 9. It doesn't get any prettier from there, especially in a long fight. So using weapons with the same delay will make it easier to time your auto-attacks and will increase your DPS by the simple fact that you're not pausing a million times in a fight to let your auto fire.
4) Practice. Get a feel for the delay on your weapons. When I first started waiting for the auto-attack notifications, I was stunning the mob and just listening and getting the "tempo" down. I wasn't using many CAs and was trying to develop a feel for it. After a while, you'll get used to when it will fire and can roll right along without thinking too much about it.
5) As far as prioritizing your CAs, debuffs should always be one of the first things thrown. That's our bread and butter and one of the easiest ways to increase your DPS (and those around you). Beyond that, it depends on playstyle. I solo a lot, so I try to land the DoT flank attacks first for added damage in a tick or two.
6) Good things come to those who wait. By that, I mean you might be better off getting yourself a weapon with 3 - 4 second delay. There are plenty of haste items in the game that will increase how quickly you swing and there are plenty of spells to increase haste in the game. Hell, we even have a HO that will increase haste. If you have two weapons with a high, equal delay, then you'll be able to squeeze in more CAs before you have to pause for auto-attack. Also, the damage spread on weapons with longer delays is typically much bigger. This makes for bigger and better crits, which brings me to...
7) Gear that adds to your Combat Art damage is good, but only to a point. It will only add up to about half (I think it's half) of the amount of damage that your CA will do. So if you're sitting around +400 combat art damage, maybe it's time to start thinking about looking at gear that will add to your crit % or attack speed.
8) Adorn your weapons. This was mentioned in the Brigand sticky posts, but it seriously warrants repeating. Waiting for the perfect weapon to adorn is a waste of time and DPS. While you're at it, maybe adorn your armor/jewelery for some more STR if you need it.
That's all that comes to mind right now, but there really are a number of ways to find your edge when it comes to maximizing DPS. If I think of anything else, I'll throw it out here.
And big ups for trying to improve and asking how! That mindset is probably the most important thing to maximizing your DPS.
DPS Question
