Lots of good ideas from some of these others... Not saying what I do is the best but I always combine shoulders with chest to get some extra reps in. For instance, I will do my chest routine which is 12-16 sets of 6-12 reps then I will do 2 types of lateral raises to hit the medial delts. You work your front delts anytime you do any type of press whether it's bench, incline, decline, or shoulder press of any type. If you focus too much on pressing and not enough on lateral movement it can give you that appearance of forward shoulders. I also have another day that I focus only on shoulders and I also only choose 1 press but multiple raises. Adding some high rows, wide rows, and reverse flyes on your back days will have a huge effect in your overall growth and appearance as well. Supersets of lateral raises in to controlled shoulder presses always work great for me as well. Hopefully this will give you some ideas.

Work on the external rotators to improve your posture and increase your bench press...

look up new shoulder exercises online and ad them into your workout. constantly change up the routine and utilize supersets, giant sets, and drop sets every now and then and if your shoulders don't get as big as you'd like id be surprised. good luck bro.

I say hit shoulder's twice a week utilizing drop set's on almost every single set. Try one of the routines that the member's suggested or pull a few exercises from each person and lift completely different then you are used to.

I recommend military presses pyramid the weight decrease the reps with each set
front and back 4 sets each

then side dumbell raises mixed each set with
front dumbell raises 3 sets of 10 reps slow and controlled movement- no swinging.

then lying dumbell rear raises 3 sets of 10 reps

then barbell shoulder shrugs 4 sets warm up then go heavy as hell but keep your form strict
then dumbell shoulder shrugs 4 sets of 10

that works for me.

alternating raises + shoulder press + delt injections

To get the best shoulders you possible can, it is important to hit all three heads on the deltoids
This is my current shoulder workout:

I begin my workout warming up on the cables with very light weights performing side front and rear exercises 1- set 20 reps

The main workouts are performed at 3-4 sets at 8-10 reps on a pyramid system

Seated barbell press (behind the head) or dumbell press (try to alternate every month)

Side raises db to hit the side delts (lateral deltoid) - do this seated for isolation and improved technique

Side raises machine - side delts (lateral deltoid)

Rear deltoids exercise DB

Rear deltoid exercice on pec deck

Front raises DB for the anterior (front) deltoid.

I then finish up on shrugs

My current shoulder workout takes 30 minutes.II keep it simple,short but intense. Its something like this. Sometimes I superset the face pulls with the upright cable pulls. I find the thicker the barbell the better. The cable face pulls I use the v bar and finish with the rope. With the upright rows be carefull not to use too much back and trap muscles. Concentrate on the muscle contraction and it will work. Ive been told by three different pro's that the upright row is the most essential shoulder excersize, as everyone can see rapid devolopment with it.

upright barbell rows
Seated DB press
upright cable rows
Cable face pulls

I end with shrugs, but I dont think these would help your posture so I wouldnt reccomend. I like to pyramid everything I do, so I go with a 12,10,8,6 rep scheme. I count each pyramid as a set, and I usually rip through em with little to no rest. And I go through 2 or more sets. Anything less and you should definelty drop the weight. I cant really do lateral raises without hurting my rotator cuff. You can do front raises with a plate, but I find that hurts my rotator cuff as well. Cable front raises if done with proper form can be something great to add in a superset with an incline db press.
Also I should add that stick to a few excersizes, dont do 2 sets of 8 excersizes, 4 sets of 4 will be much better.

shoulder press.. cant do laterals at all..either dumbbells or Straight bar or Cambered...behind the neck
or in front.)...used to love to use the Cambered bar with 275 on it..seated in a rack..yep..
now i do Viking press's with 70+ .. when i start to cycle..:)).. going to
be a lot more..

focus on rear delts it will bring your shoulders back where they belong. also a shit load and i mean a lot of side laterals. go heavy to start with and then finish with as mean reps as possible pumping blood in your delts use short rest 30-45 sec. if your shoulders don't feel like they are on fire you are not working them.

LISTEN UP:

Constantly flex your traps when you walk around the gym. I know it sounds stupid but the isometric hold WILL increase your shoulders and traps over time. Trust me, guys are always asking why I have such big shoulders/traps-- this is the secret!

i agree with j223, i love my lateral raises!

Lateral dumbbell raises made my shoulders pop like CRAZY reps of 10-16

starting out i do heavy military presses then progress into one arm dumbbell presses light weight i reps. then i drop set front, lateral, and rear raises. nothing too heavy, hit 15 reps first, ideally failing on the 15th then drop the weight for 10 reps. the pump is insane! ive been doing this for around 3 months and it def has added some good size to my shoulders

im working on my shoulders as well. you should try to do wide grip pull ups . at least 3 sets a few times a week. i can tell you, from first hand experience, that, my first cycle which is about to come to a close this friday, with pct included. all of it DONE!. within the span of 10 weeks just with Test e, and then 4 weeks of test prop and anavar. i gained the majority of muscle in my chest, my abs, arms, and pretty much upper body. my shoulder was fucked for about 6 months, so i couldn't do any shoulder excercises. now that im healed 100% , my next cycle is going to include, very heavy shoulder excercises. i have gained about a good solid 20lbs of muscle for this whole cycle. not bad at all! just take it easy and lift big. you'll see results soon enough.