Studying is a process entailing learning almost anything. It's not restricted to education, one can study a language, a skill, a routine, culture among other things. Different people got different ways of studying, different reasons for studying. For instance one may learn a language in order to use it on travel or due to career.
There's no definite ways of studying but the method of studying got an impact on one's comprehension, retention, conversant of the info under study. Most common methods of studying are passive and active study. One may have a study routine but may be bound to have mistakes or the method turns out not to work for them.

+ Poor study habits
a) Studying without a goal; having a goal helps one to atleast have a view of where they are headed to in their study life enabling one to plan, short-term or long-term schedule and be able to stick to it. A goal serves as a reminder to one's mind as you are aiming at achieving something eg passing exam, learning a language, a skill or whatever you studying. Set deadlines for the accomplishment of the goals as having a goal or aim with no deadline is as good as having no goal.There's no good feeling like the feeling of setting a goal, working on it and accomplishing it.

b) Poor time...