Do different chord progressions... I don't know, like... A-C-D, then C-D-A... Just keep swopping them about I guess.
play the chord progressions over and over again

and try this


and so on, until you can't fit one finger in each fret which is around the 15th fret

Edit: it's not that the fingers don't fit, it just feels really ankward when you go over that fret, after practicing it a lot, it turns easy
First try to master the Major Open Chords then try to barre B & F chords; at a first glance barre chords will be like climbing a mountain but keep on trying.
"I know many songs to play on my guitar but all the fish ever want to hear me play are scales."