Many people's instincts (mine included when I started) are to grip the neck like a lobster and we think if we're getting dead tones we just aren't gripping our claws hard enough. It's usually more that your finger placement is off. Try moving your fingers to different parts of the fret and use different pressures and see how that changes things. And also pay attention to where your thumb is. Sometimes you just need to change the angle of your thumb a little back there behind the neck and that in turn changes the angles your fingers are coming in, and suddenly you get clarity.
That's a bit of a meandering response, but just keep trying different things and soon enough it'll be 2nd nature to you.
I've seen uke players trying to barre with their thumb hanging 'over the top' which, to me,
doesn't seem to give them enough room to cleanly make the complete chord.
Anyway, I'd suggest making sure the thumb is in the center of the back of the neck, initially,
behind the 2nd fret (unless you're barring beyond the 4th or 5th frets)
Otherwise, a lot of it is practice and more practice - to develop dexterity and finger strength.
the Ukulele Boot Camp doesn't deal with barre chords (...yet?), but the Practice Sheets can
be 'converted' to barre chords for your use and enjoyment
In line with what the others have said above, you might want to try to bar with your finger extending out past the fretboard, rather than having your index finger stop on the g string. If you do this, it will help insure that your wrist is pushed forward and the thumb at the back of the neck. Additionally, you may find it easier if the strings are being fretted by the thicker part of your finger between the second and third knuckle.
Start on the fifth fret and practice barring each fret up the neck towards the first fret. It's easier on the fifth than the first so if you start on the fifth it gives a little confidence. Barre each fret making each string ring. I did it every night for about 10 mins and after about a week I had it. There is a YouTube video and I believe it is a Mike Lynch video that suggests this and it worked for me. Don't get discouraged!
I'm still learning myself, but these are the things that I've noticed.
I find most of the time for me it's just fine tuning the placement. The strength is there, but I need to shift up or down or roll slightly relative to the fret because my finger either isn't straight or a string is sitting in the crease by a joint and not secure. Especially with D. I seem to overshoot and have to come back a fraction of an inch to get that "E" string pinned down securely
For me it's more about switching into and out of a barre chord fast inside a song is my biggest problem. I get all tense and panic if I have to move my whole hand. So now
I make a point of working songs I really like that have barre chords in them so I have to practice switching to make it sound good.
Not sure if this is malpractice or anything, but when I bar, if I'm getting dead tones I'll just gently lay my middle finger over my barring finger. It seems nonsensical and stupid, but for some reason it works really well for me
Not sure if this is malpractice or anything, but when I bar, if I'm getting dead tones I'll just gently lay my middle finger over my barring finger. It seems nonsensical and stupid, but for some reason it works really well for me