suggestion

Dude,

These are the small but effective steps .......

Draw lines at both sides of answer paper with proper margin and with pencil. Don't use markers or colour pens to highlight ur points, but just use pencil. Whenever possible, explain ur answer with example or table or chart or figure. etc. etc.

Well above were basic steps. In order to improve presentation further, remember sections & case laws in respect of DT / IDT / Law  and 

In respect of Accounts, Costing, make your working notes properly & write ur assumptions at the end of answer  and

In respect of Auditing, remember SA (formerly AAS).

Best of Luck.