It is important to have a set study routine and schedule to always be prepared for that next test. Study schedules are useful beacause they allow you to cut a part of your day and make it only for studying. It also doesn't have to be studying alone!
Understanding and knowing what time your brain works and functions the best is important. Some people like studying in the early mornings while others like studying late at night. Most people like to study during the day. It is recommended that you try all times to see what works best for you so that you can get the most out of your studying.
Studying with friends is a double sided sword. Sometimes it can be useful while other times it can be a yap session for hours. It is good to have times when you study with poeple and alone. When studying with friends make sure you try out some studying techniques like teaching other about your subject or getting help from each other if your in the same class.
Remember, studying is only helping you so make sure to always take time out of your day to study and never forget about it. Be the Academic weapon!