Do you have any general advice for Data Sufficiency questions?

Problem solving is much easier.

Example can't figure out this one even though I took similar steps.

If n and t are positive integers, is n a factor of t?

1) n= 3^(n-2)
2) t= 3^n

They came up with C

For this example, if n is a factor of t, t must be divisible by n.
So each data can't give the relationship of the t and n.
But if you use both of them:
t/n = 3^n / 3^(n-2) = 3^2
Because 3^(n-2)*3^2 = 3^(n-2+2) = 3^n
So t is divisible by n --> SUFFICIENT