I soon came to realise that I just had to give every comp I came across a go. Competitions can usually be divided into two groups - 1. Game of Chance or 2. Game of Skill. 'Game of Chance' competitions are pretty simple to enter. They usually just involve entering your name and contact details, or sometimes just your name and email address. Not very time consuming. However, I used to think that if the prize for these competitions was a car, a holiday or something equally awesome, what's the point of putting an entry in when it's so simple that hundreds and thousands of other people will do the same? So many entries and only one prize. Now I just make sure I get my entry in regardless of how many other people I think may have also entered. How else am I going to win? If it only takes a minute (or less) to enter it doesn't matter what your chances of winning are just that you have a chance to win if you do (and no chance if you don't!).
'Game of Skill' competitions usually involve answering a question - generally in '25 words or less', or uploading a photo, video or creating some sort of artwork (drawing/colouring in competitions). Once upon a time I would never enter these competitions. I would read the question, think of an answer and then chicken out thinking my answer was too silly or too boring. Well now I realise that there are probably plenty of others out there with the same attitude meaning that less people enter this style of competition (this equals more chance of winning). I started entering these competitions regardless of whether I thought my answer was good enough to win or not and it has paid off.
Basically, you can't win prizes if you don't have a go so just do it!