Always read the Terms & Conditions (T&C) carefully. It's here that you will find all the important information about the competition - how to enter, how to prepare your artwork for hanging and any size restrictions, where and when to deliver and collect your work and lots of other important things that you may not have thought of. Adhering to the T&C will help organisers to smoothly process your applications and receive and install your works easily on installation day. Hanging an art prize exhibition is hard work and if artworks aren't prepared as asked for in the T&C it makes the volunteers job so much harder and your artwork may not be accepted into the prize.
Each art prize has their own T&C that can differ from other prizes and from year to year, so don't assume that because you entered the previous year that everything will be the same.
And finally, please read the T&C in advance of the entry deadline so you have plenty of time to contact the organisers and ask any questions. And if you're ringing or texting please be courteous and do it during standard business hours. No one wants to woken up in the middle of the night to explain what a D-ring is! LOL
Happy creating :-)