Sometimes it is going to be really hard to have a conversation with your children. This could be because you are working night shift, have limited access to the telephone, are in a different time zone, etc. Try sending an email or even mail an old-fashioned letter.
You can provide details of your week, ask for input about their week, discuss what adventures or dad dates you will do in the future, open up on your dreams and aspirations, discuss dream team coaching decisions, etc – the list can go on as long as you want. You just need to keep asking those open questions and maybe open yourself up more than you normally would feel comfortable. Try it, it may be hard at first but persevere.