How does one enter the traffic pattern when a 45 to downwind is not convenient?

Fly directly over the runway, heading toward the downwind at least 1000ft above the traffic pattern altitude. This way, you’ll have a great view of the airport and approaching aircraft.
 Once clear of the downwind leg, you can start a descending turn and set up for a 45 degree entry to a midfield downwind.
Ensure that you’re at pattern altitude before you enter the downwind. This will help ensure that you don’t descent on aircraft in the pattern. Always be aware of any arriving aircraft.
Just because you don’t hear anyone in the pattern, that doesn’t mean that a pilot in a J-3 Cub – without a radio – isn’t trying to land, too. Always fly the standard traffic pattern. Don’t rationalize some other method. That only adds to pattern confusion. Be a solution and not a problem.

Flying the standard pattern published in the Aeronautical Information Manual (AIM) will standardize pilot expectations!
Of course, at towered airports, comply with the controllers instructions!”