If you are having trouble gaining muscular bodyweight, here are some simple "rules" you can use to guide your training...
1. Simple routines of 6-8 exercises maximum per workout, and better still for many hard gainers, only 3-5 exercises.
2. Most of your exercises should be big compound movements-e.g., squat, deadlift, parallel bar dip and chin.
3. Weight train no more than twice a week.
4. Alternate two different workouts.
5. Add an extra day or two of rest between workouts, if necessary, for full recovery.
6. Master exercise form, and always use impeccable exercise technique.
7. Use a controlled rep speed. Put the emphasis on keeping your reps smooth.
8. Warm up very well-better too much than not enough.
9. Perform no more than three work sets per exercise.
10. Make poundage progression in perfect form your training creed.
11. Follow a high-quality protein-rich diet every day that provides a caloric and nutrient surplus.
12. Spread your dietary intake over five or preferably six feeds a day.
13. Experiment with protein intake. You may need large quantities to maximize results.
14. Sleep well every night.
15. Conserve your energy on your off days.