A 180° spin will require you to push off like a lateral move into a plié. Once in the plié your front foot will need to rotate, then your back foot moves to follow. The mechanics of this move require you to have weight on your back foot to start the push, shift your weight to your front foot as it rotates, then finally balance out evenly again as you resume skating. Work on transition on skates as well as off-skates. Slowly practicing the movement off-skates will help you with the weight changes needed to execute the move on skates.
Transitions Focus Sample Workout
This sample workout provides exercises targeting balance and moving through a transition. Take rests as needed. Personally, I like to go through each move once then repeat, but mix it up to match your training style! Do 3 - 5 sets of each move, adding weight if you can.