As someone who likes to pick up incidental litter along my way, my practices on this front are:

* I make a point of not picking up everything I see, rather just do an incremental bit at each opportunity

* I set a basic standard for when I should: if I literally see litter and a trashcan along the path I’m traveling - the goal being to minimize the cost / maximize the value of the effort.

Even with such minimal practices I probably pick up more litter than 90+% of people. :P

When I kayak I pick up bottles and cans when I see them. I’m not digging in the mud to get stuff but if I’m close I’ll make an effort to collect trash. Same on the beach and camp sites.