Checking up on you, calling you, hanging out with you (provided covid-safe and/or geographical nearness), remembering events or things that matter to you (e.g. a job interview, your birthday, a difficult conversation you had with X), initiating contact with you (rather than only one person contacting another), being emotionally supportive of you. Someone you feel you can reach out to, when you are struggling. Words and/or promises being backed up by actions as, as you noted, words are cheap otherwise.

In short, making their presence felt in your life so you feel comfort and care from them (even if they are at a distance). And so that you don't feel alone.