You would be amazed at how many people claimed to have their carbs set yet if they new how to perform a back up check, the carb is still way off. High end needles are generall a no brainer. The fun is in setting the low end.

With your engine running at an idle carefully remove the line from the car or pinch it real tight and wait for the engine to quit. If the engine rpms increase right before the engine quits, your low end is to rich. If the rpms just go down and the engine quits, your low end is too lean.
I try and get mine at a very slight increase.

Now each time you change the adjustment , give the engine a few reves to clear it out and chack for a smooth trnasition from low speed to high speed. With this you will have a perfect running engine.