turning to the left, from the p-factor on the prop. With the tail down, the tail-wheel gets more effective as you begin to roll, and you have to let up on the rudder. Then the tail comes up and the fin and rudder, which were low and were getting equal right and left yaw from the spiral effect, now pop up into only the top portion of the spiral propwash. The Cub will now sharply turn left unless you are quick to shove on the right rudder. As the Cub accelerates, the fin/rudder get more straight airflow and again you must let up on the right rudder to keep it straight! Whoo! And we're not even airborne yet!
One method to tame the initial gyrations is to hold the tail down for part or all of the take off run - this keeps the tailwheel firmly in contact with the runway, stabilizing directional control considerably. A touch of up elevator does wonders here; just remember to slack off the elevator at lift off to keep from climbing too steeply.
Suppose you pull the plane off early, while very slow. You are at a high angle of attack, and the p-factor (and maybe some spiral effect, too) will try to turn you to the left again. Assuming that you keep the wings level with aileron, RUDDER is the proper way to correct the left drift. If you only correct with right aileron, the plane will be in a skid, in unbalanced flight, and you're setting yourself up for a stall/snap/crash, bigtime!
Just how much prop effects affect your planes behavior depends on the plane. A pattern-type plane is affected very little. A front engined delta, which can operate at very high angles of attack (lots of p-factor) and has a very high tail (spiral propwash), is affected considerably.  You get a sore thumb from standing on the right rudder.  Your planes probably fall somewhere in between those two extremes.
Understand what is happening with your plane and learn to make the PROPER corrections (quite often with right rudder). You'll be a better, smoother pilot, and you may just save a plane or two!

it is even better to redesign parts using the kit parts as templates.  I just redesigned the Goldberg Eaglet 50 fuselage, which weighs 8.2 oz. uncovered from the kit  to 4 oz. uncovered after the redesign. km)
GLUE: Use light glue.  CA is the best for the weight, aliphatics come next, and epoxies are the worst. Where you feel you must use epoxy, such as on your firewall or landing gear blocks, use as little as possible. (The key here to all glues is as little as possible.  Making excellent joints helps to keep the glue weight down. km)
PLY: Plywood is heavy, but necessary in some spots like firewalls, landing gear plates, and some formers need to be ply. Use it sparingly, substituting lite ply or even balsa ply if you can. Where bolts are involved, you should use aircraft ply.
Even using the heavier ply, we can shave some weight. For instance, 3/16" ply is enough for most 40-size fire-walls and landing gear plates. Throw out the 1/4" stuff.
Further, use the strength of the engine mount. If it's a one-piece mount, you don't need the wood inside the bolt pattern. Cut it out, stuff the hole with balsa. The same goes for a plate for mounting landing gear.
Wing mounting blocks can be cut down.  By moving the bolts back an inch, this may allow you to cut an inch off the front of the blocks.
Ply formers can usually be trimmed from the inside, ply fuselage sides can usually stand larger lightening holes. (Or, even better, get rid of the ply! km)
CUT AND CHOP: Lightening holes can be cut in balsa fuselage sides and on the top. (You may want to keep the fuselage bottom solid.) Thinner balsa may often be used for top and bottom cross-grain planking. Hollow, or eliminate, large blocks, such as are often supplied for wingtips.
BUILD UP: Ailerons, rudders, and fins/stabs may be heavy 1/4"- 5/16" solid balsa. Building these up from 1/16" balsa skins with trusswork interiors gives a light, stiff structure, perhaps even stronger than the originals. Building up these surfaces may also be preferable to using the original solid wood with lightening holes. Skinned "built ups" are considerably stiffer than open frame construction, but not as light.
FOAM WINGS: Foam wings can also be improved upon. Note that using light wood for wing skins and minimal glue applies here, too.
Consider that the actual bending loads on the wing are greatest at the center, ranging down to near zero at the tips. Strength can be tapered off as we go out to the tips. Skin and foam may be cut away increasingly progressing outboard toward the wingtips; this is best done behind the thick point on the wing.
BUILT-UP WINGS: The same principles apply; strength continue