A good flasher is one of the key tools used to allow the modern ice angler to move quickly when there are no fish, but know immediately to stay if there are fish.  Basically there are 3 keys ways that a flasher can improve your catch rate.

Shoot flasher through the ice prior to dilling holes

Use your ice fishing flasher to find depths before drilling holes.  Use can use a bucket with water or just some water directly on the ice to allow your flasher to shoot through the ice and see the depth.  This will allow you to move quickly to find the depth combination you are looking for prior to pulling out your ice auger.

Use flasher readout to see if fish are below the hole

Once you have drilled your holes,  before you even drop a line you can run from hole to hole to see if fish show up above the bottom on your flasher.  Often you can eliminate several holes from even being fished if they are not holding any fish.  This is a way to ensure that you are not fishing a "dead" hole.

Use your flasher to position your bait in the correct depth and presentation to trigger bites

The use that most people are well aware of is the ability of your flasher to show where the fish are and lowering your bait to be just above them.  You will be able to see the fish rise to the bait as it drops or remains still.  This will also allow you to judge the demeanor of the fish and what works to trigger strikes.

The ice fishing flasher is a key tool of the modern ice angler.  Use the tips above to fish higher percentage spots a greater portion of your time on the ice and it will translate into more fish on the ice!