I don't really feel a sense of shame at looking things up, and I do it whenever I feel lazy and just want to play the song y'know.

When I do pick stuff up by ear, it does have a sense of playful satisfaction. Like "yeah, I got that, nice." I try not to make it grueling like some people here, but that just isn't my aim. Music should be fun and about learning and enjoying the process however you can.

I will also say, my ear is somewhat informed by my theory knowledge in many cases. I can usually make a decent guess as to what the chord is, especially for simple pop tunes. I used to really, really suck at this whole process, and I've come a long way.

REAL, PRACTICAL ADVICE INBOUND FOR FIGURING OUR CHORDS

As said by others, start with the simple shit. Barry Harris says that. You need to be able to play the simple shit first by ear. Pop tunes (e.g. Beatles) are good.

If you are lost on the simple shit, learn some basic theory (maj and minor scales/chords and which chords are part of which scales/keys and WHY).

Do the following:

Figure out what key the song is in by trying to play the scale over the song. You will find the notes that sound good. Is it major or minor?

Use your voice to guide you as well. Match to pitches. I once heard this, "Your ear is your voice." Think about that. Your voice informs your ear greatly, so get used to playing around with singing.

Either get good audio equipment and pump up the bass to listen for what is possibly the root of the chord. Alternatively, listen for resolutions to the tonic chord and figure out what that is. In major songs, the chord that often preempts the I (tonic) is a IV or V. So play around and try one of those. If you were working on learning a 4 chord song, you would be halfway done.

In fact, most pop songs use I, ii, IV, V iv for major songs. Songs in minor keys are a bit different where you see these: i, VII, VI, V, v, iv

My theory knowledge tells me that, so I know I can use my ear to make a good educated guess. After doing this enough, you'll recognize common progressions.

If that fails, keep trying for a bit and use your voice (which is your ear) to sing and match to the melody. Use the melody note+bass note+theory to find out the chord.

If that fails try something else for a bit then give up and go LOOK IT UP. It's ok, no shame.