To bid to make at the 5-level, you need:
Offensive values – extra high-card points, extra trumps
A source of outside tricks – a long side suit, or extra trumps and ruffing values
Controls (aces, kings and singletons) in outside suits
Very important: Control of their suit (singleton, ace or sometimes Kx)
Words of wisdom from Grant Baze:
The 5-level belongs to the opponents. Be very slow to jeopardize the possible plus position you create when you push the opponents to the 5-level. If the decision is close whether to push on, double them, or pass — then you should pass.
If you push on and go for too much, or it is a phantom, or you double them and they make it, you have a terrible result. If you double them and beat them one, you may have gained little or nothing. If you pass, in most cases the worst that will happen to you is that you break even.
This is almost analogous to a statement made by Daryl Royal: «If the (foot)ball is in the air, only three things can happen, and two of them are bad.»
[Excerpted from «Rules of Bridge» by Grant Baze, published in 1985. The full article is here.]