We talk about LIKWID and likwid-perfctr, a tool that you can use to get information from the hardware performance counters in a user-friendly way.
Multitime is a tool that you can use to repeat a command several times, and get additional information about its runtime: mean, standard deviation etc. Read this short article to get you started,
Learn about FlameGraphs, a great tool that will help you quickly find slow functions in your program.
Connection keeps dropping with SSH? Read about mosh, a simple addition to SSH that can keep your connection survive the rough network environment.