My experience:

Divide the rolling circle in 4 quarters. Do not try to perform the full rolling circle at once; try the 1st quarter , then ad the 2nd and so on. Abort the maneuver whenever you feel is necessary, try it again.

You can use any of the 4 different ways to approach the rolling circle:

1)From your horizontal level flight line: starting from left to right; option a) roll right, option b) roll left.
2) From your horizontal flight line starting from right to left, same options as before; a) roll right b)roll left.

Throttle management during the maneuver is a must in case of having strong wings or even moderate winds; depending on the direction you might have to add some throttle if your plane is against the wind. This will render a constant speed of your plane along the path of the rolling circle.

Same thing for the aileron; although the rolling circle assumes a constant aileron rolling rate; the wind can play games on your rolling rate.

Above all try this at home using your flight simulator; then when you master this on the computer, try it a the field; you will notice that the wind factor would also have to be considered to perform the magic behind performing a properly executed rolling circle.

Enjoy