And another ukulele hero - Jim D'Ville
The best way to develop your musical skills is to test them, challenge them - and develop your musical "ear".
Check over the list of 3 chord songs on the 3 chord song page here... choose a song that you're familiar with, and have a go at strumming it without a song sheet.
Chances are, the first chord will be C, because when you play a 3 chord song with C, F and G7, you're "in the key of C" and C is the chord you'll start with and end with - it's the "home chord".
You may well hear when the chord should change - and you've only a choice of 2! As you go through it, and it will likely be by trial and error for a while, try to remember the right chords as you find them. Practice changing chords in the right place - it will get easier. It's rather like doing a puzzle, but the right chord will sound right, that's the thing.
Gradually you will learn the song. A boost for your skills, and a big boost for your confidence!
I love this approach and I've always played by ear from childhood, being desperate to play (piano, recorder) and unable to lay my hands on sheet music, I used to work it out. It was and is fun....I still do it - it's only practice, and perseverance. I'm not brilliant at it; (Jools Holland learned to play piano by ear and IS brilliant...)
Of course, 2 and 3 chord songs are only the beginning - as new chords are added to those three in more complex arrangements, the interplay of major and minor chords is an entrancing revelation.
A big ukulele exponent of playing by ear is Jim D'Ville. Check out his website, there's great stuff on there - and a link to his "3 Chord Club" - worth more than a few minutes!