Ah,Amit,don't let anything spin your wheels,my friend.
Clean:An uptrend is made up of higher pivot highs and lows,downtrend lower pivot highs and lows.........the action is smooth.Curvature,gradient all smooth........not scratchy,lines all over the place.
Ugly:Scratchy,lines taking out previous pivot highs,next day previous pivot lows......too many gaps,lines,no clear cut patterns,etc
In a nutshell,look for charts that allow you trade without giving you nightmares..........There are charts out there with beautiful patterns and pivots,and then there are the others.........
Sorry for being as vague as possible..........difficult to communicate beauty or anything abstract except by "not this,and not that".......more of indications,pointers,.............not really descriptions and definitions.
Just keep track of the yummies and the uglies as I keep shooting my mouth off........think you'll find the pattern of what I am looking at and what I am pointing to.
Saint