If you are approaching an airport and the traffic pattern is on the opposite side of the airport from where you are (you will need to fly through the pattern to get to downwind); the recommended technique is to fly 500' to 1000' above traffic pattern altitude (TPA) directly over the center and perpendicular to the runway in question. As soon as you cross the runway, start a descent that will take two minutes to get down to TPA. The first minute continue perpendicular to the runway and the second minute start a turn to intercept the 45 degree downwind leg and enter the pattern at TPA.

If done properly you will notice that the turn to intercept the 45 degree downwind is opposite the direction of the traffic pattern. So if the runway has a standard (lefT) traffic pattern, the intercept turn will be to the right.

Your answer is in the AIM. 4-3-5 "WHEN APPROACHING FOR LANDING, ALL TURNS MUST BE MADE TO THE LEFT UNLESS A TRAFFIC PATERN INDICATOR INDICATES THAT TURNS SHOULD BE MADE TO THE RIGHT."

This means that I should enter the traffic pattern on the 45 to the left down wind. I should be monitoring CTAF for any traffic and scanning the area also.

CFI, CFII, MEI

I prefer personally to fly the upwind at pattern altitude slightly to the side farthest from the downwind traffic, enough that I can see the runway below. This allows me to check for existing aircraft or obstructions on the active runway, runway condition (whether its wet, snow/ice covered, or damaged), and maybe even get a glance at where the wind is blowing relative to the runway.

I haven't seen anything written on whether or not this is a best practice, the upwind has always been vague to me as well. Interested in hearing what other pilots think!