here are my experiences- i graduated and went to work - after two years, my employer says we will reimburse if you want to get a m.s. degree at night - so as a formality i needed to take GRE, but people at work and at the school would see my scores so i didn't want to come off soft haha
i started with a practice test from a book. then, i went back and read the instruction closely -- knowing the format saved time in the future. i could just glance at the instructions to be sure.
then i looked at what i got right and wrong. i remember i missed similar math questions, so i read that section in the book. i didn't study the rest of it. as for verbal, i didn't do any specific studying but i just tried to pay closer attention to words in daily life. if i heard an unfamiliar word, i would try to think of a good definition in my own mind. if not, i would look it up. now that didn't actually build my vocabulary or anything, but it got me used to quickly thinking about the meaning of words and got me to focus.
then i got my concentration up. on the weekends, i would do uninterrupted study sessions for as long as the test would last. i did my budget, i read long books, etc. just concentrating with no music or snacks or interruptions. i did this for a month or so.
then, the weekend before my date, I did a second practice test and felt ready. i took the test at a sylvan learning center. i didn't have trouble focusing and nothing surprised me, so i think i was about as prepared as i could be.
now i am not saying anything i did actually improved my abilities, but it kind of set me up so i would do the best that i could do - keep in mind i had been out of school for two years so my test taking skills had eroded.
hope all that makes sense and sorry for long post