Level 11
My list has a lot of overlap with George's so this seemed like a good place to reply.  I strongly recommend #3 "Make new contact with clients to review their pay stubs and see how deficient their withholding is in light of this years changes."  I've done a fair number of these already and it can be pretty ugly.  I had one of my clients add $1,000 per paycheck in FWH thru the end of the year to try to catch-up.  (Which reminds me, I need to study the new/draft W-4 for 2019, 'cause we're gonna want to turn that off in January!)

One of my CPE instructors last year had a good idea.  Keep an eye out as IRS releases new/draft forms/pubs.  Read the "What's New" sections.

Vacation starts on Sunday.  Anyone near LAX?

Today was mostly filing/clean up.  I filed my (one) 6/30/18 FYE 1120 today (yes, I got the extension filed by 9/15 instead of 10/15).  I met with a late 1040 client, got signatures and efiled.

I "soft" fired a client today and I think I'm going to use that as a template for others:

"Effective immediately, I'm firing all of my last-minute clients.  Boom, there it is, YOU just got fired.  <Mic drop>

<Pick mic back up>  The good news though, is that you still have an opportunity to be a brand new not-last-minute client for next year.  I'm putting a 3/15 deadline down for everyone to have their tax data in to me or they can go somewhere else."

And then I proceeded to tell him the things he could do NOW that don't have to wait until next October 13th to be done.  I've decided I'm tired of extensions.  Every year it gets worse.  Life's too short.

For some of my small Sch C clients we meet in Dec to get 11 months of bookkeeping done.  I make this win-win by giving them a discounted "off-season" rate and then I'm not slammed in March doing 12 months of bank recs.

I'm going to try to get organizers out in December this year instead of the usual late-January / early-February.

So yeah, I have a pretty busy Fall this year.