My suggestions would be practical ones for anyone just leaving.
If you've been hanging out for a very long time, plan to grieve a loss.
Plan ahead for the first night or afternoon where you'd usually be in a fellowship somewhere. All that stuff you wished you could do that night? Do them, start simple.
If you still need/want to tithe, research a place to give your dollars. I gave my 15% to Head Start for awhile cuz it's a program I highly believe in.
If you need a church family, start simple like going to a public event they have; bake sale, etc. Great relaxed way to meet new friends and listen.
Take a freakin' vacation where YOU want to go.
Re-structure your down time and make attempts to shove aside the guilt when you're not using this time studying Acts or Revelation or planning the next event.
Get a new address book instead of just crossing out those fools who won't or can't talk to you anymore. If you leave them in just crossed out, it's a daily reminder of the loss.
Leave your ministry (or whatever) material up and laying around for a time and maybe take one or two down or put away slowly. This stuff has been a part of your life for a long time, it looks "empty" there without it. If you toss or burn or otherwise give away things in anger or grief too fast, the regret might be great later.
Plan your answer for when you run into old "friends", as you surely will if you stay in area. Don't get caught off guard without a retort and don't avoid forever. You decide, though.
Don't canel your Subscription to their mag or literature immediately. Look at it and use it as a reminder why you did whatcha did; it was right.
Don't second guess yourself, it takes time to adjust to such a total and complete shift and it will feel normal again.
Been wanting to read the most "devlish" book you can get your hands on but knew they'd find out about it? Read that bad boy. With a glass of wine or your fave brew. Then discuss with someone who's also read it, w/out a shred of guilt. Leave out on your coffee table in plain sight.
Buy a brand new clean and fresh budget book. Keep old one with their structure for tax purposes, but start over fresh for yours.
Spray some WD-40 on old bumper stickers and get 'em off.
Do nothing drastic in a hasty manner. This is a loss, it's a shift in life and major decision shouldn't be made for at least a year in some circumstances. (This one was the one I learned the hardest way possible).
Relax as much as possible.
If your spouse/partner/suite mate/ kids/others aren't leaving the organization with you, don't stare at them in anticipation of them understanding how much better you are and why don't they get it. Strike a compromise for daily life and stick to your half of the deal.
Rough day? Call that old friend who left before you and see if you can re connect; they'll likely be thrilled to big brother/sister you.
Don't call everyone you ever hurt in the place right away. You know you're remorseful for some stuff and would like to start repairs, but overwhelming actions often brings overwhelming answers and it can seem undone later, making do over necessary.
Take your time.