Do you have tips to avoid DNF's? I have had two successes and about 20 fails.
Assuming you use old pochmann:
Yes, practice until you master the method your are using so you don't even have to think about it, your main focus should be the memo, the execution of the method should be very easy.
When you have to think about your method too much and you focus on how to shoot to each spot you can't focus on your memo and you get confused.
Know your lettering scheme perfectly, you should be able to say a random letter and INSTANTLY know where it is on the cube, and not just know where it is but also what setup move and perm you need to do to solve it. All of that without even thinking about it.
If you don't have a lettering scheme and for example you use UF to talk about the UP-FRONT edge and not a single letter (for me it's C), get a lettering scheme ASAP, it will makes things much easier. (I suggest you use the speffz lettering scheme, look at the wiki to know what it is).
At first it might seem hard to get used to it and you will find yourself going "A-B-C-D-E-F-Ha! there it is" on each piece you want to memo and solve, but after some practice I promise you will be able know the name of each piece and it's color easily.
Watch this video by Noah:
http://www.youtube.com/watch?v=3JNpJaRccRE
I also suggest you don't try to do full solves, try doing edges only solves, do a lot of them until edges become really easy for you.
Then move to doing the edges, stopping to see that you did everything alright and then memo and execute corners.
When you do edges fast enough without too many breaks and corners too, move to doing the full solve, you'll see how suddenly it is very easy.
Another small tip from Noah's video which made my solving much easier: Memo corners first before edges using image pairs memo, there are not many corners and you can memo them all by just about 2-4 images in your mind. After the images sit well in your mind, begin to memo the edges using audio-memo, use the lettering scheme to make a sentence and repeat it over and over while memoing, after you're done and went through all the edges just keep saying the sentence while executing the edges, when you're done with it's first part you can get rid of it and start saying what's left over, you'll be done with the edges before you know it. All you have to do now is remember the corners memo which you used images for, and execute them.
I hope this helps you.