Corks 

I can't stress enough about getting a good cork for your wine.
I recently took a bronze in my first ever wine competition which was a national event.   I also recently visited my cellar to find a cork or two on the floor with many others pushing out.   I'm not saying its all the cork's fault, but I am looking for a good cork that I can recommend to you.   Out of the 30 bottles I started with, I only have 12 left that haven't pushed the cork out.   The fermentation has completed as far as I can tell.   I'm somewhat frustrated with this and am looking to try some synthetic and winery grade corks now.

I've tried a couple of different types of corks, and am still searching for the ones I'll always use.
There are different grades, sizes, etc of corks out there.   There are: 

Short Corks Long Corks...  Size does matter.
Short corks are easier going into the bottle, and easier coming out of the bottle. However, there are some problems. Short corks have a shorter life. When driving a corkscrew into them to remove the cork from the bottle, some corkscrews will penetrate the cork and leave cork chips on top of the wine. The long cork is of sufficient length that the corkscrew stops short of penetrating the cork. For the short term wine, the short cork has about 6 months less shelf life.

When buying corks, make sure that you are getting what you pay for. A good deal is not always the best deal. Some regular grade agglomerates are now being passed off as winery grades.