Despite what you have been doing so far in terms of utilizing the Trash Bin as a temp holding area for possible deleted items, you really need to elevate your thought process to think of that bin no different than you think of your own trash can in the kitchen or somewhere else in your house. I don't think you make a habit of pruning through that trash when it's time to take it out and say "Oh, I don't want that thrown out just yet.".
If it's any consolation, I too do this sometimes with my trash because I was so used to doing it with my Windows based trash bin, but Apple doesn't see it as a place to selectively delete items. To them, Trash is trash (no longer needed). I personally have two levels of trash. There's stuff I don't want filed anywhere else anymore, but may run into the odd chance I may need to dig it back up in a few days to a few months, and then there's stuff I just don't want anymore. To me keeping those "I may need these later... maybe" files in the Trash bin made sense from the standpoint that if they did get deleted, no big deal, if not, at least I can still go to one area and find them. I do the same with emails. If I truly do not want it, it's Shift+Del for a permanent deletion. A normal delete that takes it to the deleted items bin is a "Soft Delete" to me. đ