Hey Nlindler,
I will brief out how I do it.
1. Read the question very carefully. write exactly what you have to find out on the scratch paper to keep you focused on that thing.(Convert the long question into a math simple statement)
This is imp because mostly GMAT plays with your mind, and gets you focused somewhere else and hence you mess up your time as well as the answer.
You should read the Manhattan Guide, and practice this part as in how to read & break the question into simple expression. Practice it and master it. I will say it again this is most imp.
2. Pick up the choice (A {First} or B {second}) which you see is easier to read ..
3. Do a math. Lets say you picked A. If A alone does the job, Eliminate B, C, D. Look if B can do it alone as well. MArk D else A.
4. If not A, look for B, eliminate A, D. and move on with B, C and E.
Remember when you pick A, and are not confident. Quickly leave and move to B , and start from B.
I have seen that for me there is always a fight b/w C & E.
Rest keep practicing and you are gonna hit what you want.
~abhi