Everyone's barn is different, but I think the grooming and tacking up is a great time to do some training. In other words, don't tie your horse. Also, think about what you would do if you were standing around talking with friends. Have two of your friends each grab one of your arms. They can give you six inches to move around but that's it. And you have to hold your arms up, although you can lean on your friends. Now stay that way for 30 minutes. Remember, you can't move more than six inches. Try it and tell us what you think of cross ties. And also remember, you understand the exercise. Your horse doesn't.
It can be in the same place you cross tie, but just put a lead rope on her and drape the rope over your arm and start grooming her. If she moves her feet, move her back where she was. You might have to do this 100 times. Don't get irritated, just move her back. She'll get the idea she has to stand. The only key here is you need to get all your stuff out and near your horse when you start. Also, Rome wasn't built in a day. Don't go gestapo on her, she can scratch an itch or look around, but you want her to keep her feet still. You might need to put her back 100 times today, 90 times tomorrow, etc. etc. And as you probably can guess, don't be in a hurry. Horses need time.
It's neat how many little things get worked out but just getting your horse to stand still while your groom her and tack her up. I am amazed at the people who can't ask their horse to simply stand still, but have no trouble hopping on their back and thinking they will be able to get a positive reponse to any request up there. Like stopping. Think about it.