Problem 0: Learning basic piano technique, sightreading, scales arpeggios, theory
Solution: Classical piano lessons up to Grade 5
Problem 1: Learning how to play from fake books like iRealbook ProSolution: Learning all the basic chord inversions from the encyclopedia of jazz chords by Jack Long. Learning about jazz RH chord voicings, the circle of fifths and A and B chord positions from The Jazz piano book (Mark Levine). Also covered even more effectively by The Jazz Piano Step-by-Step Course.
Problem 2: Learning how to more easily and effectively improvise over common chord changes.
Solution: Finding out from the The Jazz Piano Step-by-Step Course about diminshed scales and that I can just use the 1 chord scale on a 1-6-2-5 progression instead of the 1, 2 and 5 scales.
Problem 3: Learning how to play in time so that the music flows
Solution: Finding out from The Jazz Piano Step-by-Step Course about the importance of practising together with the metronome.
Problem 4: Learning to play something from start to finish
Solution: Finding out from The Jazz Piano Step-by-Step Course about the importance of this.
Problem 5: Overcoming the tendency when performing to stop playing and repeat the passage where I made a mistake.
Solution: Read some advice somewhere to "treat every mistake as the beginning of your next solo". Also playing along to iReal pro and being tasked with keeping up with the backing track (which waits for no man).
Problem 6: Overcoming getting bored with my own playing
Solution: Inspiration from The Jazz Piano Step-by-Step Course to introduce more variety with different voicings, scales, chord progressions, dynamics, playing outside etc
Problem 7; Aimless 'practicing'
Solution: Structure provided by The Jazz Piano Step-by-Step Course.
Problem 8: Adding the rich sound of bass tenths in my playing
Solution: sometimes I like to roll the bass tenth (1-5-10) I just play the root and fifth with my left hand and the bass tenth note with my right hand instead
Problem 9: Overcoming stage fright
Solutions: If at all possible I prefer to use my own piano when playing so I don't get thrown by the unfamiliar touch sensitivity and tactile response of a different one.
If possible warm up well beforehand with scales, voicings etc. Feeling free to turn down people's requests to play if you don't feel like it. Avoiding the temptation of alcohol. If possible shaking out nerves beforehand
Using the 4 out for 8 breathing technique while playing (simplified version of 4-7-8 breathing). Breathe in for 4 seconds, exhale for 8 seconds. Repeat. Also, Phil from Phil Best Music Youtube channel's advice: Start off playing a bit slower than I normally would, (nerves cause me to speed up my playing) and focus on maintaining a steady rhythm (rather than playing rubato style).
Closing my eyes from time to time allows me to really 'be present' with the music and not getting distracted by what's going on outside this way it's easier to get into the flow state as well.
Problem 10: Overcoming the boredom and rigidity of playing to a metronome
Solution: Playing to the metronome off beat instead of on beat as advised in The Jazz Piano Step-by-Step Course. Playing standards using iReal pro app.
Problem 11: Growing up in a house with an overly loud and bright acoustic piano, which meant being asked most of the time to keep the noise down and caused anxiety (Am I playing too loud? Am I playing badly? Is the piano out of tune? Waiting for the penny to drop)
Solution: I wholeheartedly recommend getting a silent / hybrid or digital piano with good action like the Yamaha Avantgrand series, Casio GP or Privia S line.