Indenting and aligning can be a great way not only to improve readability but also to facilitate debugging. For instance, I like to indent statements within a do loop and line up my END statement with the corresponding DO as shown below. This not only makes the conditional code easily identifiable, it also helps when you have nested DO statements and are trying to keep track of where each ends (also useful for tracking down missing END statements).

if condition then do;
var1=vara + varb;
var2= var1 * varc;
if var2 > chkpt then do;
var3= var2 / 2;
var4= var3 + vard;
end;
end;