I have a question . . . after you take photos of these dogs in dog parks, do you try to sell them to their owners?

I don't. Those are more for my pleasure of shooting. I think if you did such a thing, you might creep people out. I could be wrong though

To me, people buy if they are expecting that someone will be there as a photographer. If someone walked up and said "I took photos of your dog, here's my card" I might only be annoyed.

Yeah, that is kind of what I thought too. So, it is more for your enjoyment than for money.

Shooting different subjects in varying lights gets you accustomed to your gear, and how things will turn out in different lights

If someone calls for an outdoor portrait session, I know where, and when the light will make good photos. I am still on the steep side of the learning curve, so I take every chance I can get to shoot things

Horses and dogs are my favorite, and what I intend to specialize in. The old adage of shoot what you know is what I am going for.

In answer to the question, do I try to sell these pics to the owners?

I approach people, admire and ask about their dog, ask if it's okay to photograph the dog, give them my card, and offer to send them the (400 x 600 pixel) "snapshots" without any charge or obligation if they send me an email to let me know they're interested.

On the back of my card it says that I'll send them "snapshots" without any charge, but if they would like the original digital files to make enlargements, or if they would like those files post-processed, they're available for a very "modest" charge.

To date no one has taken offense, refused permission to take pictures, or otherwise reacted negatively to my approach. Several people have sent emails requesting the "snapshots," a couple have asked for the original digital files, and one person has asked that I come to take pictures of her and her dog (which I haven't been able to arrange to do yet).