1. EFATO whether straight ahead or turnback - speed is life. If a turn back with (possibly) 45AoB, add some knots to the normal gliding speed (on the Bulldog with 75 kt glide I'd use 85 for a T/B). In the climb attitude the IAS will wash off really quickly if you don't get the nose down pronto, so: Select the gliding attitude, select yr landing field, select flaps/sideslip/manoeuvre to achive it.
2. Whatever you do should be preplanned and briefed. eg "up to 500' land ahead/L/R. after that t/b L/R etc etc" so it's already in yr head. I used to brief my students that once they'd started the upwind turn they could continue the turn to land on the airfield; before that land into wind on a suitable field.
3. There is no one size fits all to this. It will depend on experience level, currency, training, wind, terrain etc and (as above) the crucial thing is to make these decisions before you apply T/O power.