Slack / IM often, don't demand a response instantly though, async & remote go hand in hand.
Put important stuff in email not slack/IM
Have a company wiki
Prefer video calls for alignment
Write to each other often, spend time crafting written narratives, 1-pagers, amazon 6-pagers etc. to share ideas, make people read them, use google docs or ms word online and get comments inline in the document using those tools, follow up on video calls to confirm alignment.
Gitlab has a handbook for this stuff, they are a 100% remote business and very open about their practices: https://handbook.gitlab.com/
Put important stuff in email not slack/IM
Have a company wiki
Prefer video calls for alignment
Write to each other often, spend time crafting written narratives, 1-pagers, amazon 6-pagers etc. to share ideas, make people read them, use google docs or ms word online and get comments inline in the document using those tools, follow up on video calls to confirm alignment.
Gitlab has a handbook for this stuff, they are a 100% remote business and very open about their practices: https://handbook.gitlab.com/
consider personal readme's if your team is a bit larger (example): https://gitlab.com/swiskow/swiskow