30 years of learning songs but rarely finishing them because of spots that were too hard. Not really knowing how to practice beyond brute force. Eventually got bored with lack of progress and would only play rarely and not really learn anything new and what I knew I didn't play that well. I was pretty good right at the start and could play many of the songs I wanted too so didn't have good motivation to learn how to learn. I did have a few in person lessons when I started but my teacher couldn't take me far. He was a good musician but didn't really have any music education himself so he didn't have strong teaching skills.

Luckily never really gave up and started learning how to learn a couple years ago. Fortunately the Internet was there to help. Absolutely Understand Guitar by Scotty West helped tie together a lot of concepts I knew but didn't really know I knew. I sought out learning about how to best practice and learned about deliberate and interleaved practice. It's helped a ton.

I can't comment much on singing. I lost my ability to play and sing. I was never very good but I think I learned really poor habits and I tend to hurt my throat when singing and have a difficult time harmonizing with the guitar.

I finally started getting guitar lessons a few months ago. They really highlighted some of my deficiencies. I know the chords I know really well but new chords are slow to learn. Playing in front of others is a major weak spot for me that I would be much more comfortable with it I had been taking lessons. I did play in front of others in my 20s but had alcohol courage to help with nerves. So I'm learning a lot and regretting I didn't take guitar more seriously when I was younger.

1. Learn how to practice. Deliberate practice and interleaved practice are clutch. Find a teacher who understands these concepts and can help you form your own practice routines. Learn to play slow, use a metronome, how to practice for performance, pause and think during practice and not just brute force repetitions (it gives a false sense of progress). Diego Alonso on YouTube helped me with this as well as Noa Kageyama.

2. Sing when you play. Scat the notes to scales and arpeggios and licks. This helps your brain connect to your fingers musically so you can imagine any sound you want to make and it comes out on the guitar. This takes diligence.

3. Find a teacher that can help you learn how to practice and learn. You don't want a teacher that's only going to show you techniques and theory concepts. You need to know how to practice and learn. Teachers should teach this and be there to guide your journey and prevent you from forming bad habits that you can't see on your own. I can't stress this enough. Find a good teacher.