[Help] [Discussion] We just earned our Intermediate Trick Dog Title! Our next step is to add distractions - how do you go about adding distractions?

We adopted Sasha a little over a year ago from a rescue group and it has been a bumpy road but she's finally settled in and we've realized that she is super smart! We've already taken a basic obedience class, a dog sports foundations class, and a novice trick dog class. We passed all with flying colors with a few exceptions. It would take 3-4 classes for her to actually settle and concentrate on us and not the other dogs or humans (she LOVES dogs and new people). By the end of this last class, we had her focusing on us for ~90% of the hour which is very good for her! But once a new dog or person walked in (usually after class when the next class was coming in and we were staying behind to chat), it was like we had to start all over (we just walked out every time).

We are still working on loose leash walking so we don't walk often but when we do, she will pull, whine, and bark towards dogs, people, cats, squirrels, etc. So that is saved for training time in the coul-de-sac when there are no people or animals around. We walk with a gentle leader too!

She gets plenty of exercise - both mental and physical. Every other day, we go for a bike ride in the early morning. The distance is between 0.5 miles to 3 miles depending on the day (it's purely on concrete - it sucks I know, but it's what we've got and I alternate between the longer distances with the shorter ones very often, so 0.5mi one day and the day after 1mi and then the day after 0.5mi). After work, we play with the flirt pole (a life saver) for 40 minutes to an hour. And after a rest we train! She loves to free shape with the clicker and had a blast in our trick dog class.

I want to take introductory agility in the next few months (maybe 3-4) but I'm afraid her recall on the first day will be horrendous because of the new environment and I really want to work on this! (She is terrified of her leash getting caught on obstacles so we had to take it off in trick dog class but she did really well and always came back.)

So, basically my question is: how can I gradually add in distractions so that we are successful?

And if you need extra information from me, let me know!

Bonus pics! http://imgur.com/a/vviR1 (any guesses on breeds???)