1. Purpose. The main purpose of a transmission is communication. Even though there are conventional ways to say certain things, if you don't say it conventionally, as long as you are speaking plain simple english and communicate what you intend, the job is a success. The other pilots would much rather hear what you have to say even if it's unconventional than to not hear you at all.
2. Brevity. Often radio traffic is busy. To help reduce the traffic, keep all transmissions short. 5 seconds is typical. A 10 second transmission is considered long.
You should use this template so that important info is conveyed clearly and concisely.
WHO you are talking to
WHO you are
WHERE you are
WHAT you are doing
WHO you are talking to once again in case the listeners missed the initial part of the transmission.
If the pilot in the aerobatics area is being a jerk and won't allow you to enter the area, you have not much option other than to know the boundaries of the practice area and stay clear until the aerobatics traffic leaves. Always be polite. Even if they guys says "stay out", then respond with "roger, paraglider staying clear of the aerobatics area until the aerobatics traffic has left the area, have a good day, Redlands.|
Now let's say that while initially listening you don't see or hear any aerobatic traffic. Stay monitoring, and transmit your progress every 5 minutes or so....
Redlands aerobatics traffic, paraglider, 1 mile west of the dam at 5 thousand 7 hundred feet, circling and climbing, Redlands. And keep your eyes open for traffic.