1) Be there
It is easy to be busy. You know you care and you will be there for them in the hour of need and distress. The challenge is to take out the time in the hour when it is good to be around because family is not a minimum viable product where you can negotiate the requirement.
2) Be cognisant
It comes naturally to some and requires efforts for others to earmark things. One way to be part of your family even if you don't live with them is to make an effort to ask and remember what's going on in their lives. It is something like a networking session but in this case you are not making contacts, you are making their day.
3) Surprise!!
How about showing up at home without a notice just to see their faces brighten up? The fun doubles when it's an occasion where they long for your company even more. It doesn't have to be all proofread and demonstrated like a software release or showdown - let them enjoy the surprise. The "no surprise" work policy can rest in peace when it comes to family.
4) Appreciate their efforts
You know that a simple thank you message goes a long way - management science 101. Do you think it works the same with family ? Perhaps not as they won't quit on you if you don't give them their fair share of appreciations. The question is what happens if you do? They will hold on to it with pride and love.
5) Tell them what you really feel
Trust them with your feelings - It is that simple. Just let them know what you think and feel even if it's a hurtful breakup or a happy story. When you miss them say it out and when you feel you'd rather be alone just say it out as well. Be transparent to them about your feelings without worrying about any impact on the relationship or appraisals.
