Declutter the Dock
Rule: get rid of cruft you don’t use; it just degrades the experience and causes visual confusion.
The dock contains all kinds of cruft that I don’t need, or that I don’t need immediate access to. Right-click or control-click on undesirable characters to Remove from Dock. You can always put something back later if you decide you want it; drag it back into the dock.
This is what my Dock looks like after I clean it up, but before I install the applications I use.
This is what I like, change it in System Preferences.