Look behind boxes and clothing. Stairways pose threats as well. There are many techniques for stair clearings. Choose a simple technique and move only under the cover of your search team. When you reach a danger area, stop and allow your partner to move up and cover you, while you clear.
Hallways can be complex.
There are usually many doorways and exits in the hall. If no cover is available, stay alert and be prepared to drop to a prone or kneeling position. You and your partner can alternate the sides of the hall for maximum coverage to the front. Like most of your skills, your building search techniques can get rusty. Especially, if you don't do it often.