Unfortunately its a case of picking one of the bright stars and using the finder on the camera,i even use the moon. Also it's a 17 year old canon 300D, no live view of rotatable LED panel. i have to take 5-10 second shots with a bahtinov mask on and look at them, then change focus a tiny bit and re shoot, it can take blooming ages and involve rolling around on the concrete at 2 am....not fun