All of these drills can be done using short fins.
The important thing here is balance, not speed.

Balance Drills - Notes

The first two shots to the left illustrate the Back Balance drill, above water and below.

In both shots, notice how much of the head is in the water.

In the both shots notice the knees near the surface. The knees and feet should just barely disturb the surface.

When new swimmers begin doing this drill, they tend to drop their feet deeper and deeper into the water. To counteract this tendency, make an effort to make a small splash at the surface every now and then. (But don't look back at your feet - that will make you sink!)

Try not to arch your back, but rather round your shoulders slightly and press back into the water, leaning on your spine.

The third shot illustrates Side Balance - Nose Down. Practice with that arm extended until the position is totally comfortable.

Then bring the extended arm in to your side - this is the Side Balance - Nose Up drill. This will present more of a challenge to your balance than it did with your arm extended.

When the side balance becomes comfortable, try rotating your body from one side onto the other, keeping your face looking straight up. When you are very comfortable with these drills, you are ready to begin a similar seqeunce, but this time face down.