I generally get preliminary radiographs done of hips and elbows when the dogs are around 18 months of age. It's important to wait until the growth plates have closed. Taking x-rays too early can indicate subluxation on young Labradors.
Dr. Shong at Bohicket Veterinary Clinic does a wonderful job. He gets positioning perfect and also takes multiple shots. He is conservative in his assessment as well. I've always felt confident in his abilities and assessment for OFA submission. He always uses sedation for the positioning because he wants to be able to manipulate the legs into the correct position.
Once the x-rays are processed, we review them and he will point out what he likes and doesn't like. We don't submit them at this point. If the joint structure looks great, we keep our fingers crossed until the finals are submitted at 2 years of age.
Getting OFA hips and elbows done is a major milestone with breeders. It is imperative to have good positioning and a good x-ray machine when getting radiographs done.