First of all, tight hips do not exist by themselves. The experience of contracted hip flexors is a relationship between many functions, most notably the hips, low back, and belly. Here are some options to help alleviate this experience
One of the major ways we construct feelings of anxiety is by pulling ourselves up and away from the ground. A sense of physical support from the ground is basic to any sense of emotional security and well being.
Many people come to me with sciatica. One of the causes of sciatica is the lack of movement in the hip joint and an excess of compression in the lumbar spine, which sends the lovely shooting pain down the leg.
If you don't stay mobile, you will narrow your range of options. Aging will become a path of limitations instead of a path of freedom. This is true even for people who put effort into athletic movement or working out.