"Field Trips"

One joke that many homeschool parents make among themselves is that anything can be a field trip. When you have young kids at home with you all day, you have to take them with you on the most mundane errands. So a trip to the bank becomes "finance education" and the grocery store "home economics". For kids with special needs, these types of lessons becomes a truly important component of homeschooling.
As my daughter has Asperger's syndrome, there are many parts of social interaction that she does not understand. Things that most people pick up by observation, without thinking about it, she has to be specifically taught how to do. Purchasing something at the store is fraught with multiple, subtle, non-verbal interactions as well as the added difficulty of money.
As we move through our day to day lives, I try to be aware of opportunities to teach Melissa about the types of interactions she will be expected to engage in all her life. Any time I ask Melissa to go anywhere or do anything out of the routine, her reaction is to say "no thank you" (at least I've managed to teach her the correct, polite response). Given the choice, she would never go anywhere or do anything out of the ordinary so I often just have to tell her that we are doing something, rather than giving her the option to decline. If I have errands to run, I think about the value that can be added if I take her with me, or if she should continue working on what she is already working on at home, alone (Melissa is at an age where she can be home alone for a few hours. Obviously, you wouldn't have this option with younger children or those that can not be unsupervised).
While we are out and about, I judge her level of comfort before I try and teach her anything. For example, if she is already stressed by the noise and confusion of being at a baseball game, having her purchase a hot dog herself could be too much for her to handle. But, if we are at the Costco, a trip we take every few weeks and that she is relatively comfortable with, purchasing a hot dog on her own isn't as daunting an experience, and she still learns the steps involved in that interaction. Then, next time we are at a baseball game, we can try to transfer that successful experience at the Costco into buying a hot dog at a baseball game.
This is just a basic example but an important one. Being aware of opportunities to teach your child as well as being attuned to your child's needs at the moment should always be together in your mind. But, as you become more experienced at homeschooling your special needs child, these opportunities and needs will become more apparent to you, and easier to reconcile.