Who you are
What you want
Then:
Who you are
What you are
Where you're from
Where you're going to
Where (laterally and vertically)
Where you're tracking to
KISS = Keep It Simple etc
eg.
Westbury Approach,
G-ABCD,
request Traffic Service
Then:
G-CD,
Cessna 172
from Borton
to Walden,
15 NM South of Westbury
altitude 2500 feet (Wessex 1008) VFR
tracking to Wells (Squawking 7000)
(That from an ATSOCA controller of 28 years......and RTX for 10)
(Personally I think QNH and squawk superfluous 'cos the controller doesn't care 'cos you will be given fresh ones anyway)