There are a number of steps involved in responding well to a person who is potentially suicidal.
Step 1: Noticing when someone may be at risk and being alert to the possible mix of risk factors is a vital first step of engagement. Notice especially changes in behaviour like sleeping or eating patterns.
Step 2: Engage the person in a serious conversation (as opposed to an in-passing one) about how they are feeling.
Step 3: Give reassurance and information.
Step 4: Encourage the person to get appropriate professional help.