Practical strategies for increasing one's passion and excitement about research?
I find that a good way (for me) to get excited about my research is to work with some inexperienced research students - high school and undergraduate students.

Mentoring these students reminds me of the things that excited me about research when I first started: mainly, that we can come up with some problem that we think is interesting, that hasn't previously been solved, and then go ahead and solve it. I still think that is so cool, and seeing that reaction in my students reminds me all over again :) Also, I get to feel like an expert in this scenario, which helps makes me more excited about my work.

Generally, I find that spending time with others who are passionate and excited  encourages those feelings in me, too.