I wish that I had some horticultural tips to share for my success in doubling the number of tulips in this section in just one year. Unfortunately, I can only chalk this up to "dumb luck," with one possible additional reason being that this spot receives regular watering in spring and early summer.
In reading over some tulip cultivation websites, I learned that I also correctly practice the habit of letting tulip leaves wither and die, and that the relatively dry soil during summer and fall is beneficial.
So perhaps "dumb luck" is an understatement on my part, but I did not knowingly set out to double the blossom yield, as I might with the deliberate purchase of, say, hair growth shampoo. I do, however, enjoy the color they bring to my yard at a time when leaves are just starting to appear on the trees.