HERE IS THE PROCEDURES.

1. Have treats on your person (later you may use a toy instead, but it helps to start with tiny, tempting treats, lots of tiny pieces), but keep them out of the dog's sight. To initiate the attention sequence, say "[Dog's Name]!" and YOU MOVE ABRUPTLY away from her. If you want to say "Heel" or "Come" or "Front" or "By Me," that's fine too. The main thing is, say the name--this is going to become the word on which she will learn to look at you--then MOVE.
2. When she moves with you, quickly PRAISE her. This is where you would use a clicker if you wish to use that method, but a word of praise is fine, too. Then instantly whip out a treat and give it to her. Do not show the treats until you are ready to give one. This prevents the treat from becoming, in the dog's mind, an actual part of the command--or a bribe. Each time you give a treat, align it between the dog's eyes and yours. You want eye contact from her with that treat. Soon you will find her seeking your eye contact. Always praise her when she does that, and it's fine to give her a "free" treat for doing it.
3. Okay, you're not done. When you do this sequence, always do at least 3 to 5 in a row. That means each time you 1) say the name, 2) move, 3) praise, 4) whip out a treat and 5) give it. This doesn't necessarily take up a bunch of space, since you want it all to happen very fast. The movement is not over a great distance. You can move one direction the first time, back the other way the second time, etc. But always at least 3 to 5 repetitions in a row before you release the dog's attention. This is what teaches her to SUSTAIN that attention on you until you release it.
4. Practice this exercise everywhere, including at obedience class. You can do this with a toy, especially once you have taught it to her. But don't rush to get away from the food. Food is the easiest thing to deliver with this split-second timing, and will greatly help you in establishing the pattern of attention.
5. By always praising before you give the treat, you are also building up your praise in the dog's mind. This will allow you later to praise at that correct moment, and be able to deliver the treat (or toy) a bit later (when you have to walk across the room to get one, for example) while the praise maintains the continuity in the dog's mind between the action and the reward.

This ability to get the dog's attention any time you want it will serve you when working her around other dogs. Not only will you be able to control her, but if you are consistent about taking her attention off the other dogs EVERY time she gets too interested, you will find that the sight of another dog will start causing her to look at you! Praise this, of course!

Many people believe that socializing a dog with other dogs is for the goal of creating a dog who can just play with any dog she meets, anywhere, anytime. This is not a realistic goal for many dogs, especially after maturity. A much more reasonable goal for her is to teach her to pay attention to you when working around other dogs, and ignore them. You'll notice at dogs shows, this is how the experienced handlers manage their dogs. It's not like a big dog park with all the dogs playing together.

The attention exercise is not extremely time-consuming. Just take a few moments and do it with her in every location where you go together. It's surprising how quickly it becomes habit for the dog to look at you when you say her name--and equally habit for you to positively reinforce her every time she gives you her attention. People will comment on how much your dog loves you, and the obvious bond between the two of you--and they'll be right!