Always better at motivating others than myself with this (mainly through hypnosis), but I have learned a lot along the way.
It's been mentioned, but food really is ideal to growth. Make sure you are getting enough protein and the right amount of healthy fats throughout the day, and especially pay attention to what is consumed pre and post workouts. Though powders/supplements can be helpful, try to get as much of your essentials from real food as possible. (Sadly this does get expensive).
I'd also say to find a good balance with what you work out when. Some general advice I've seen is beginners doing full body workouts and alternating with rest/cardio days (how much cardio also depending on goal). Then for more advanced, doing something like chest/shoulders triceps one day, legs the next, back/biceps the next, rest day, repeat. This is just one of many options but the point is you need to give your muscles time to rest/heal so while it's okay to do biceps/triceps same day if that's part of your workout schedule, you wouldn't want to do biceps one day and then triceps the next. But you also don't want to wait too long before you hit the muscles again - sometimes more advanced bodybuilders can do this, but usually is less helpful if trying to start growing muscles. The point is though that muscle grows while resting.
Smaller reps with heavier weight is often recommend for strength and smaller weight with more reps for size. Personally I'm hoping to boost both
Take it slow, but not easy - really allow yourself to feel the tension and contract those muscles at the peak.
Change your routine once in a while - I've heard various on this, I like 4-6 weeks myself.
This is based mostly on general information I've seen about the web and as has been mentioned, it can vary for everyone so you can try different things.