Being a teacher praise was ingrained in my training. Like JamesJohn points out notice the little things. Almost go looking for positive things. With my H a simple thanks when he helps with dishes or calls during the day. At times I will add "thanks for ..." so he knows exactly what I appreciate. Even if you say at the end of the day " I appreciated...".

One thing I contiue to work on is noticing H's way of appreciating me. Sometimes it is not so obvious. But I'v learned when he asked if I need help with what ever or if there is anyting I need when he runs an errand is his way of say I appreciate your time and what you do.

It may seem awkward at first ( it did when I first started teaching) but if you look for positives and get in the habit of say "thanks" or "I appreciated that" the words will become second nature.
Good Luck
Bumbling