These tips are from personal experience and from a course I did.
If you've ever been to a shelter or pet store, people always seem to pick the first dog they see or find adorable before they have look at all the others. This can cause many problems for the owner. A dog must suit your own lifestyle such as fitness, high, medium or low energy dogs. A recent stint at a shelter showed my just how often people rush to get a dog or don't consider their own lifestyle in the dog.
1. Before you go to the shelter. Ask yourself do you have the time, energy and means to effectively look after your dog. Yard space, fitness, financial costs (vets!!), TIME. Be honest, a dog is a companion for up to 10+ years and shouldn't be punished by laziness or impulse buying.
2. When looking to adopt, be honest with yourself and ask am i an energetic person and can I always set aside time for a 30 minute - 1 hour walk every day. Dogs mirror the personality of their owners, if you are low energy person don't buy a energetic dog. This will cause all kinds of behavioral problems that will be home made by you.
3. Dog responsiveness. When you choose a dog take he/she to a spot where you can show them toys (shelters have heaps) or other dogs.If you get treats for the dog whilst on your walk, you can also determine how to train them by finding out if they are treat or toy driven to maximize your training. Also walking around obstacles is another good step to help you determine whether to the dog is calm, shy, or aggressive. I know shelters write profiles before adopting out, but they are often off the mark as dogs behaviours change when on their own in a cage but also act different in different environments. If they put you in a cage outside with your dog you won't find out much, ask to walk around the shelter.
4. The walk. Even though the dog doesn't know you, all dogs will be a follower or a leader. Going on a walk with the dog helps determine whether the dog pulls you along, tracks or hunts (chase's animals). All these mean the dog is ignoring you, you want a dog that responds to you.
5. Don't become emotional about the dogs past. Always Focus on the present. People who tend to try and make up for their 'bad' past tend to over do the dog with affection, treats, free roam and the dog ends up becoming the leader as he/she has always gotten everything it wanted from you.
6. Structure. It must start as soon as you get your new pet. You must instantly become the leader and enforce boundaries and rules. Exercise, discipline, and affection. These are the 3 key elements in creating a well rounded dog. If a dog is exercised every day, you eliminate boredom and also makes the dog more content, as well as keeping them fit and healthy.