What has helped me in the past is everything that Henrik described... a good test is are you sure, or are you guessing? When you go to strum the chord, are you sure that the chord is going to sound correctly, or do you just think you've got it pretty close, then strum, "pradong..! you hit a bum note, oh well, move your finger a bit... there, that sounds better..." If you're finding yourself in the latter, which many of us do, then just like Henrik advises, slow it way down. You can even shut off the metronome, forget about playing in time, just strum one chord, then change, when you know you've got it, strum again. I still do this when learning new chords.

Something else that helped me and may help you with the "creepy crawlies" is when you lift your fingers off the fretboard, make the shape of the chord before you place your fingers. Focus on bringing that shape to the fretboard so that all fingers touch down simultaneously. It can really help you clean up your fingering.

I'd like to mention too that this kind of practice usually progresses geometrically... so if you're going super slow one week but playing really cleanly, then the next week you're playing just a little bit faster, you won't have to go on like that for years to finally get smooth & fast. Instead, you'll likely struggle to get it smooth, then you'll get it at a very slow tempo, improve a little bit, and then take a huge leap forward and it will just seem way easier. It takes discipline and work to sort this stuff out, but its worth it in the long run.