Slowly advance the throttle. Use every inch of runway you have while learning to take-off a taildrager. it should take from 5 to as much as 10 seconds to move the throttle from idle to 75% (and most light models should be off the ground by then) If you slap the tick to full throttle, you WILL ground loop.

Use a full up elevator briefly, to help keep the tail down, making the tailwheel more effective until the rudder gains some authority. (as it gains speed, let off of the elevator)

A LITTLE toe-in can help. Too much makes the plane want to nose-over.

If possible, shim or shift the landing gear to put the axles directly under the leading edge of the wings when the airplane is level. That can often cure a "squirrly" model.

As you gain experience with taildraggers... you can apply the throttle faster. The coordination of rudder, elevator and throttle becomes automatic.