I've been DMing a game, and playing a game on Skype. Low tech and gets the job done!
I've played on Roll20, and it's fun. But futzing around with the map (fog of war, battle mat, etc) is fun as well. I've created maps and stuff on Roll20 to use in Play-by-Post games. I think if you do maps by hand, that's half the battle right there. Likely only because I'm not so hot with the maps. What edition you playing? For AD&D, OD&D and OSRIC there's a crapton of tools here (highly recommend all the goodies in the Wizardawn application) and it's all free: https://osricrpg.com/tools/
But I'm sure any thread searching for ideas and tools will get the job done as well! Good luck! I've been DMing 1e my four daughter for years now, and the two oldest (16yo and 18yo) have DMed 5e as well. It's such fun playing with your kids!!
--Ron--