I wouldn't recommend practicing changing two chords for more then say 10 minutes a day. You will just get bored and start to hate playing alltogether.
Also, you should practice different guitar skills not just one and then move to the next. So lets say you are now practicing switching between chords. You can also practice other things like playing scales, Pulloffs/hammerons on 1 string, picking techniques etc. according to your skill level. Practicing only 1 technique every day is not really gonna get you far.