I've learned to speak some Mandarin. What helped me a lot while talking is using Google's Translate function to see if I get the tone right.

It's free and fast. It's very helpful when you want quick feedback.

I learned a lot from it about the pronunciation of consonants as well. The k-sound has way more air in it. You need to pronounce it as "kh". Same thing with the t-sound.

I just came back from a trip to China and it was noticeable how much more people understood me. Still need to work on vocabulary though...