There are exceptions to almost every
rule, but I'll be compiling a list of basic rules of thumb that are
generally a good idea to follow. This is a list of tips and tricks
that will help keep you competitive in SC2.
1) Keep building workers out of all of your nexii,
hatcheries, and command centers. Never stop. If you've maxed out
your workers in one base and you're workers are running around
instead of mining than...
2) Expand to a new location and send workers to the new location.
Build another nexus, hatchery, or command center before your first
base has run out of resources. The best thing you can do is to
expand as soon as you can, without leaving yourself vulnerable to
being overrun.
3) Don't leave resources such as gas or minerals lying around.
If you have resources sitting around doing nothing than those
resources are useless to you. If you don't spend them you might as
well not have them. Always use every mineral and gas you have. If
you have 5000 minerals lying around than build a bunch of gateways,
hatcheries, or Barracks and start pumping out cheap units in large
numbers. Your resources aren't doing you any good if you don't use
them. If you must, expand and start collecting more gas .
4) Don't focus too much on static defense. A few photon
cannons, spine crawlers, or bunkers can help you hold off your
opponent in the early game while you build up a more comprehensive
army, but don't expect them to hold off forever. Attack/armor
upgrades only affect your units, not your buildings. Eventually your
defenses will become weak and crumble to upgraded siege units such
as brood lords, siege tanks, or colossi. Even worse, your opponent
might just go around them and destroy your unprotected base.
5) Learn to balance economy and your army. From time to time
in your game think "ok, can I afford the minerals to build another
expansion?" and "Do i have the forces to defend that expansion?".
Knowing when to expand and when to focus on your army take
experience, but in order to get better at it you must first try.
6) Don't focus only on winning with
starcraft 2 cheese. Sure you might beat some newbs, and it
might look like easy wins for a while but it won't last. Eventually
you'll fight better players and you'll find your cheese has stopped
working. You'll be forced to use non-cheese strategies only to find
out you don't have the slightest idea how to beat a good player
without cheesing. Cheese can be a fun and amusing change of pace,
but it shouldn't be the only thing you do.
7) Playing with the mindset that something is "cheap" is a good
way to lose. Don't whine every time you lose in a way that you
didn't expect. Instead watch the replay, think about what happened,
think about what you could have done to stop it, and if you still
can't figure it out come to the forums and ask what you could have
done differently. The game isn't perfectly balanced but in most
cases it is a better idea to learn how to stop strategies instead of
whining about how you lost to them
8) Build only as much supply as you need and build it as you need
it. Don't waste 2000 minerals on overlords, pylons, and supply
depots that you don't need. Remember, that's 2000 minerals you could
be putting toward troops or on a nexus/hatch/CC. Build your supply
units just before you need them. An overlord at 9 supply, 15 supply
, and 25 supply is all you really need. There's no need to build 4
supply depots before your second rax.
LOL:

Hope these tips help!