Learned my Morse from a set of tapes made for amateur radio operators, got to about 10-12 wpm off them, then went to Lonnie in 1980-81 and got my speed up at the AMC using the "Datong Morse Tutor" machines (little grey boxes that sent random groups, letters only or mixed, at speeds up to about 35wpm), also copied Ships press from Sydneyradio on 8.841Mhz to get up to speed. Taped a lot of the press on 8Mhz as a training-aid for the AMC, they probably still have the cassettes somewhere. As it was addressed "CQ" I figured it was public domain so taping it wasn't an indictable offence.
Got to about 28wpm as my fastest receive speed, but at sea we usually worked 16-18 wpm on a good circuit, error-free so no need for repeats. Got us off the circuit quick so someone else could have a go. Good mode of comms at sea because it cut through bad static and was flexible since operators could slow down if the circuit was poor.
About the only thing that really killed it was bad fading (QSB). I got a bollicking off Sydneyradio (VIS26) one evening when I called up for a telegram about sunset and was turn number 6 on HF. By the time it was my turn the band had died and I had to get a QSP via Thursday Island (VII) on MF.
Copied the last transmission from Perthradio (VIP) when maritime Morse finally shut down. Some Morse still can be heard on the HF bands (apart from the ham-bands) around 8Mhz at night, usually from mainland Chinese stations.
Practicing by mentally sending the number-plates of cars etc is good practice. The amateurs at the bottom end of 20 metres (14 Mhz) are also very useful, although a lot of them I suspect are using keyboards and computers to read and send. Really well-formed Morse can be read in your head at quite high speeds...you start hearing entire sentences in your head, not just words-at-a-time. Trying to write it down slows you down - try to read it in your head. When writing it down, lag the code by a couple of letters so you are not tempted to "journalise".
Morse is also a lot like music. It has a rhythm, a beat and a cadence. Certain passages of Morse (such as the beginning of a Sydneyradio traffic list on MF) are as familiar to me as the opening bars of my favourite music. If you can carry a tune you can probably learn Morse.