Hi there,
It really depends where you are. The UK standard is an overhead join at 2000' AAL followed by a deadside descent to circuit height and crosswind join no matter which direction you approach the field from.
However 'Local procedures' are common in the UK. Usually there are good reasons - airspace congestion, instrument holds/departures passing through the overhead at 2000', gliders/helicopter circuits on the dead side/noise abatement etc.
This means that you'll often find airfields with circuit height joins to either deadside, downwind, base leg or even straight in. However you will find few (if any) places that do a US-style 45 degree midfield circuit height join or a European-style 90 degree midfield circuit height join.
The usual rule for unfamiliar airfields is to read Pooleys carefully and give them a telephone call to find out the joining procedures. That's why so many airfields are officially PPR - basically just to get you to call them to find out the local procedures.
Cheers!
foggy.