Here is a hand from a national tournament that comes to show that it is better to take immediate action at low level rather than waiting and make a later "safe" bid, after opps have limited themselves.
North decided to pass 1st round because of the broken spade suit and having only 9 hcp. Later on, he felt 2♠ was a safe balancing bid: 5 cards, lenght in diams, overcall on a suit both opps bypassed. In fact, the situation was perfect to balance with 2♠. You can't have a much better hand to bid here, so what could go wrong?
Well, as you can see, a lot could go wrong. East doubled to show a max 1NT response and there the matter rested. After the inevitable 1 down, South pointed out to North that an immediate 1♠ overcall would give take the hand off his chest and put partner in the picture. It would go..
West North East South
..1♦....1♠....1NT..(end)
and North could now pass 1NT without a qualm.

Help

West North East South
..1♦...pass..1NT..pass
pass....2♠.....X (end)