Join in the circuit or not????

As a newly qualified ppl(h) UK based I am now starting to visit new
airfields for the first time.

Often I could easily land without going anywhere near the circuit.
This can sometimes benefit other traffic but what do experienced
pilots do?

Do you always join in the circuit?
When would it be better to stay out of the circuit?
How do you decide?

I know that air traffic (r/t) or lack of will sometimes determine the
outcome but I would welcome the view of an experienced Fling Wing
pilot.

Thanks