WHAT IS YOUR EXACT GOAL?
If you want to lose weight, think full body work outs! This doesn’t necessarily have to mean circuits. Stay off machines. Train standing up as much as possible. Train explosively. Do a lower body exercise followed by a upper body exercise most of the time. Add some intense cardio. If you want to put on size, shoot to stay in the 6-12 rep zone, use moderate loads, think about compound sets (ie. 2 exercises for the same muscle groups in a row.) If strength is your goal, think low reps heavy loads! Your goal is ultimately up to you, but know what it is and how to properly train accordingly.
DO YOU KNOW YOUR SCHEDULE??
A work out is only as good as the quality you give. Be realistic. Don’t set yourself up to fail. Find the few times a week and the hours you can put it in a great effort and stick to those days and times!
BEGINNER OR ADVANVCED??
If you are a beginner, master the basics first. If you can’t perform basic movements, use your body weight until you have learned and can maintain perfect form. Then load patterns. Also watch high volume training (lots of reps and exercises) at first. High volume training may leave you really sore if you are not use to it, and will hinder your body’s ability recover. If you are more advanced on the other hand, my advice comes as a surprise to most. However, my advice, most of the time is to actually do less but harder. Meaning, take the few exercises you are awesome at and add some intensity, via weight, rep schemes, set types, less rest, etc. Keep working on getting better at them!
DO YOU RECOVER??
If you eat like crap you will feel and look like crap. If you are not discipline to go to bed on time or care enough to improve the quality of your sleep (tv off before bed, hot shower etc) than you will not reach your full potential. Take care of your body and listen to it. Foam roll, walk, stretch the list goes on.