Yes, I know it's a challenge. Just start out placing your finger down in the bar position, and plucking each string to make sure it's sounding properly. Make adjustments to the bar finger as necessary. Guard against using excessive pressure, when played correctly, bar chords are almost effortless. If you observe your your fingers turning white or cramping up, your using way too much pressure. Oh, and for practice, start with the C6, all open strings, bar, running it up and down the fret board. Once you can bar open strings comfortably, then adding fingers for other chord shapes will be much easier. I'm not sure I've described that right. Just use the bar finger across all strings, nothing else. And move that up and down the fretboard. Don't get frustrated. It will come.