How young is baby? If super young you might want to try nursing twice on the same breast before switching to nurse twice on the other breast. Not just to get all the hind milk, but to make sure you are all drained on that side. Esp when newborns are nursing practically every hour on the hour.
They tend to get sleep at the breast -- wake baby up. Change diaper or something. Just to be sure each nursing block is hitting 15 min or better. Nursing often and deeply rather than "just little sips" will help make sure you are getting all the milk out to reduce clogging.
If not a young baby -- are you nursing often enough to avoid clogged ducts? Older babies want to play so easily distract in the day. May have to experiment to get baby to nurse without distraction.
What about your clothing? Is it breathable? Not too tight? Check your bras to make sure they fit well enough to support but aren't too tight.
More tips here:
Really all of kellymom is a huge help.