I have a problem of opening too many tabs. A major reason is that I forget to close previously opened tabs. This problem is worse with the safari default tab ordering behaviour which opens a new tab next to the current tab.
It just doesn't work for me. I like my tabs to open after the last tab so I can order tabs that are useful to me and tabs I can discard.
Instead of writing an article on how to change the tab ordering behaviour, I decided to link this. It's pretty good, check it out