ACROSS

 1  Divvying a very quiet beginning, otherwise turning into this with a gin sling. (12)

10  The main description would be nothing to write about, with a couple of points to end everything. (4,3)

11  Oriental makes a point, with a harsh word. (7)

12  Cuddly thing with a possibly strange appetite is a knock-out according to the description. (5)

13  In San Francisco or Salt Lake City, what you may do on a shingle. (5-4)

14  On which you might write down your thoughts, I see by the sound of it–which is rather noble! (10)

16  See 3 down

18  Keep on talking and talking about what is a plaything for an angel. (4)

20  Hangs around with, and forms part of the group of partners. (10)

23  It has a middling association with Longfellow, having lots of money to throw around like crazy! (9)

25  One who overindulges, sort of like Perot. (5)

26  It’s French law to introduce a sibling briefly when you have infestation with the parasitic eyeworm. (7)

27  Breed of cattle taken as part of the Communist questioning. (3-4)

28  One might hear it said on the first day. (5,3,4)

DOWN

 2  Color in the top of your head, putting the time ahead. (7)

 3  and 16 across When you run in it, you might have to jump things. (8,4)

 4  Members of a certain order, where a well-known musical family takes their chairs, when slightly disturbed. (9)

 5  In Sappho, per antiquarians, one can find an elaborate musical drama. (5)

 6  Came out, but gets called into court. (6)

 7  One of the Windward islands, not quite great, and absolutely nothing to the Spanish. (7)

 8  Proceed diligently, as testators sometimes have to do. (4,4,1,4)

 9  Not in the required fashion. (13)

15  A brave nomenclature for what the tot might consider a choo-choo. (4,5)

17  The first word of 28 precedes this on certain occasions, with the following given to you. (8)

19  Somewhat scarlet, but beets might represent such on the table. (7)

21  Possibly a topic a cook might dish out. (7)

22  Admits being the way down supper, in part. (4,2)

24  Overoxidized, but if you are, you’ll have to bone up! (5)