Before I give you my delt routine, let me give you my philosphy behind it.
I don't buy into that shit about how your shoulders get enough work from training other bodyparts (front delts with chest, rear with back, etc..). I simply don't believe that indirect work in exercises for other muscle groups will ever be more than just a warm up for shoulder training. And if it is more than indirect work, chances are that you are doing the exercise completely wrong in the first place.
I also base this routine on good old volume training because #1 it stimulates the muscles more adequately than low set high intensity training and #2 the constant pushing of blood into the muscle helps in fascia stretching with is very important for growth.
This shoulder routine looks long. Roughly 24-27 sets. Which sounds like a 2 hour workout. The layout is basically :
7-8 sets side laterals reps 10-12
7-8 sets front laterals reps 10-12
7-8 sets rear laterals reps 10-12
3 miliatary press reps 8-10
But it only takes about 45 minutes tops. You are not doing forced reps or negatives or drop sets or any of that shit like that which does nothing but compromise your form and risk injury.
Look at it this way. Your side delts are what?? as big as your two fingers? You dissect that muscle and you will see the actual side delt is not very big at all. So why you want to throw heavy weight at such a small muscle? You can't possibly stimulate it enough without incorporating and recruiting additional muscles. So your side laterals, effectively become a compound movement for the whole shoulder girdle. You target that tiny muscle with high reps, volume sets and you push that blood in there to stretch that muscle from the inside as much as you can. When you start training balls to the wall with the utmost intensity, throwing that weight up, getting those extra forced reps, dropping the weight and continuing on... you are just grinding the hell out of your socket and putting the entire SITS foundation muscles at risk of injury. Why take that chance when you can accomplish the same results with just an extra set, which is safer. Not to say this is candy ass training, you are still going to train hard. But when you reach the failure limit you are going to acknowledge it and accept it rather than stubbornly try to overcome it.
Every third workout you can change up and do something different. Something based primarily around pressing movements. Two of my favorites are behind the neck presses done with free weights as the smith machine locks you into a path range that may not be natural for you based on your body structure, arm length, etc.. (when I lower the weight, I only bring the bar down to about mid ear level, any lower you are begging for trouble, so don't do it) and the second pressing movements will either be dumbell presses or reverse front presses on the smith machine (for safety reasons). This exercise, you grip the bar under your chin with a grip that resembles the completion of a barbell curl. Hands shoulder width (thumbs facing out, palms facing you, but your hands directly in front of your delts, you shouldn't have your thumbs out past your shoulder width.) Then just smoothly push the weight up. Sort of resembles a reverse underhand grip pullup when you are lowering yourself. But you are sitting and pushing. Hard to explain but you can sit at your desk and try it to get the right idea.