I just found a warvid from me playing kanuks in some tournament in '06... and dang! I was horrible back then.
Here are some basic-advanced tips which focus on improving mechanics and can bring them to the next level. Most of this is well known and written down more detailed in sc:bw guides at teamliquid for example. Since i have seen alot of war2 players play in real life, i know almost all of them are having deficits in their mechanics and settings. But not all of this will fit to your playstyle.
HotkeysGenerally try to use as many hotkeys as possible. You should be able to use all hotkeys without looking at your keyboard. If you don't use a lot hotkeys yet, start to integrate 1 or 2 hotkeys into your playstyle and once you mastered them, go on with the next hotkeys.
Macromanagement (building stuff)The '0p':
Bind your first hall to '0' (Ctrl+0), second '9' etc. and use '0p' to build peons. This will allow you to build peons while you micro your units and after a while you will build peons without even thinking about it.
Build units from your barracks:
-Bind them to 0-9:
You can either build units using hotkeys ('5g6g') or just click the unit icons ('5click6click'). I prefer clicking because i use 1-4 for raxes and '1o' is just not confortable for me.
-Spacebar:
This jumps your screen to the place where the last action happened (a grunt was build but also a building finished, you get attacked etc.)
-Bind f2-f4 hotkeys:
With shift+f2-f4 you save a position. You can bind the area where your raxes are to f2 to quickly jump there to build units. This also is very nice when you have to micro in two areas to quickly switch between them.
-Click through raxes:
Just click through the raxes and use a hotkey to build the units, this is probably the best way if you have alot of raxes.
Use Hotkeys for upgrades:
Back then when i used to click upgrades, it happened that the upgrades didn't go, usually because of a "dirty" click while moving the mouse quickly. Hotkeys are faster and you are sure the upgrade will go, there is nothing worse than losing a game because bloodlust didn't go!
Micromanagement (unit control)Send a bunch of peons to work:
You have a bunch of peons standing around and only a few of them are carrying ressources? Send them to the gold mine or lumber and press 'g'. The empty peons will go to work and the others will return goods. This is insanly fast compared to microing single peons.
Use doubleclick to select units:
When you doubleclick a unit, you will select all units of the same class on your screen. This is very fast and especially usefull when your units are spread out or inbetween other units.
Game settingsMouse Scroll and Key Scroll settings:
Set it to as fast as possible (Menu -> Options -> Speeds). This will take a while to get used to but it makes you alot faster! If you are not confortable at all with the fastest setting, set it to the second fastest at least.
Warlat:
Always enable warlat. It will reduce the latency and make your units respond faster and better to micro. To enable it, go to Menu -> Network and set it to extra high, wait a few seconds and set it to low again. Warlat is built in war2combat.
APM (actions per minute)This is how many clicks and hotkeys you make in avgerage per minute. Use war2observe to see your apm. When you have mastered the hotkeys, try to increase your apm. War2observe is not 100% accurate and doesn't count a few hotkeys. For example 0-9 bindings and f keys, so you might get fooled when you start using those hotkeys and your apm gets lower.
Caution: War2observe may crash your war2, i will post a guide how to prevent crashes soon.
MouseThis is just a best practice, you can be happy with whatever settings you are feeling confortable with.
Windows Mouse Settings:
Speed 6/11 and no mouse acceleration. With this settings your mouse won't skip pixels (1 Mouse dot = 1 screen pixel) and is the most accurate. Some mice have built in stuff like acceleration and angle snapping etc. which you can't dissable in some cases.
If your mouse feels too slow now, increase the DPI of your mouse if possible, else use higher windows mouse speed settings but you will lose accuracy.
I for example play with 1000 DPI (dots per inch) which means i only have to move my mouse ~0.5 inches to scroll the full w2 screen in width (w2 resulotion is 640x480). Thats pretty fast and yet i can control it perfectly.
KeyboardWindows Key(s):
If you accidently hit the windows key(s) and jump to the desktop, crack them out of your keyboard and use alt+tab to swich to your desktop.
The "marked" Key:
If you tend to miss an imporant key, for example 'P' to build peons, switch your P key with the "5" key from the numblock. The 5 Key has a little bubble (just as the F and J keys) and the next time you build a peon, your finger will get a feedback and you can be sure that you hit the right key.