Short answer should be "whenever I legally can". These days it's "whenever I remember".
State law is also a factor. In WA, there is a list of places concealed carry is off-limits (courthouses, schools, bars, etc) but there is a provision for leaving the gun concealed and secured in a vehicle for example. So in my case, if it’s not on me (whether I'm at someplace it’s prohibited, or swimming in a lake somewhere), it’s securely locked away in my vehicle.
I'll typically be carrying when walking around downtown, going to movies, restaurants, hiking on trails, shopping, etc.
If you haven't already (and no doubt you have but I’ll do my civic duty and say it anyways), make yourself intimately familiar with your state and local laws regarding concealed carry if you're considering it. But if you walk to work/school and don't ever go anywhere else (you do go other places right?
) then you simply might not have many options, perhaps pepper spray?