Motovation
Motivation is enhanced firstly by becoming more realistic and aware of the task ahead and secondly by "psyching" yourself up with constructive self-talk, on your ability to face the challenge and its anxieties. Much avoidance behaviour is a defence against the fear of failure, so deliberately switch your focus onto the process of studying, rather than the ultimate result (the desired pass or high grade). Resolve to do this studying for yourself, not for anyone else.
If there are certain topics that you dread and therefore have a tendency to avoid, break them down into smaller bits; incorporate morale boosters - an enjoyable reward after each small task is completed. Find out what works for you and what doesn't - avoid the latter. This may sound obvious but it is surprising how many students persevere with unhelpful and unconstructive methods of studying simply because they always have and it feels strange or worrying to abandon something familiar. Maybe you would find it easier to work with a friend or in a group, or at the library. You may try using a more flexible time-table perhaps studying less (then paradoxically achieving more). Minimise the competitive atmosphere by ignoring the amount of work others might be doing - focus on your own approach.