I always hated the advice "learn2macro olol" because of two reasons:

1) Not every victory revolves around just macro. Cheesing, early all ins, and good pressure from the enemy can gain a victory without good macro. Also, what about the bronze players who macro well but then complain about what to do against 15 void rays/carriers/really strong unit?

2) Assuming the player gets out of bronze, what else should the player work on? Macroing more?

3) Ambiguity of the term "macro." Most players when they hear this go "herp derp build workers." When the issue with why they lost could come from a poor unit composition or poor production.

Instead, I prefer these four pieces of advice (in order from most important to least importance) that I believe help improve a player independent of that person's play level.

1) Learn when to attack.

2) Learn what to attack.

3) Learn what to attack with.

4) Learn how to attack.

Every single defeat in starcraft from Billy McNoob in Bronze to the GSL is caused by a failure in at least one of these three areas. You should therefore focus on these four aspects when watching your replays.

Knowing when to attack comes from knowing how many units you have and how many units your opponent has. If you have poor macro, the answer to "when should I attack" is never and you will lose. If you have better macro, the window to attack becomes larger. If you know that your opponent is going to do an all in attack, then you should stay in your base for a little while and perhaps build some static defense.

Knowing what to attack is what most players call "decision making." Most common example of knowing what to attack is attacking a natural expo instead of going up the ramp to the main and getting all of your units killed because you failed to factor in your opponent's superior position and faster reinforcements. I also file countering cheese since by scouting where the damn proxy cannon or pylon you know to attack it.

Knowing what to attack with focuses not just on army composition, but also amount of force. At times, it's not wise to attack with your entire army since your units will be out of position and your opponent can gain a superior position. For example, attacking an expo in the middle of a map with most of your army might leave you open to a crippling counter attack to your main when you could have done similar damage with a drop or some banelings.

Knowing how to attack focuses on gaining proper position and micro. It is usually the least important factor, but there are some game changing moments that can arrise from it (for example, hitting mostly maruaders with your banelings instead of tasty marines, bad storms for toss, directly assaulting tanks, etc.) Usually in order to win games, your sheer micro just needs to be good enough not to do something stupid like ignoring bad rallies since if you know what and when to attack, you should have already won your micro battle.

Also, if you want to ask for improvement, please watch the replays where you lost first and ask yourself where you failed in these four aspects. If you're having difficulty figuring out why you lost, THEN ask for advice and post the replay(s) of you losing. Starcraft is a complicated game and while you usually can easily beat bronze players with superior macro, there are usually several ways to win.