Sometimes when you put things off, it is all to the good because when you get back to it, circumstances have changed in a positive way.
In this case, more and more Schleswig-Holstein records have come online in recent years — and someone else has done the transcription of the Danish/Low German handwriting!
Thanks to the surge of online documents in the past few years, I’ve been able to extend my Danish great-grandfather’s maternal line and paternal line [Ahnentafel 28/29 on my pedigree]. This great-granddad is my mother’s maternal grandfather, a first-generation American.
My 2nd great grandma Caroline (Thomsen) Holst’s ancestors
My 2nd great grandfather Peter Nicholas Holst’s ancestors
One site I’ve used in recent years is Danish Family Search, wherein volunteers are transcribing the various censuses taken in Denmark. And the duchy of Slesvig (my ancestral home) was part of Denmark until Bismarck invaded Slesvig in 1864 and, after the Austro-Prussian War in 1866, the territory was annexed by Prussia. 
Members of my own family headed to the United States during the decade or so, with my 3rd great grandparents, Johann Carl Thomsen and Maria Erichsen, both in their late 50’s starting all over leaving their home behind for the hills and valleys of Sonoma County, California.
With respect to https://www.danishfamilysearch.com, I have built out a tree of my Danish line and added census records, where available, to it. In some cases, the census records were already transcribed by volunteers. More recently, I’ve been able to find Danish censuses online at FamilySearch.org   and MyHeritage.com; those also have been transcribed. Then I do a search at DanishFamilySearch, and add the applicable census to my family tree there, as well as doing a partial transcription of my own family’s household.
Highlighted in yellow above is Carolina Margaretha Thomsen, aged 2, with her mother Maria Erichsen, aged 23, and her father Johann Carl Thomsen, aged 25.
Above is a screen shot of the 1855 Denmark census for Peter Nicolai Holst, aged 8, with his younger Georg, aged 1, his mother Anna Dorothea Johannsen, aged 32, and his father Peter Holst, aged 34.
It’s certainly much easier to find my ancestral households now than 2 – 3 years ago, which is when I first began using DanishFamilySearch. If you haven’t been to DanishFamilySearch, I’ll walk you through the site below. Regions other than Slesvig-Holsten are likely to have more records (e.g. church books) available, simply because they are in the Danish Archives. For Slesvig-Holsten, you also have to research in German archives. You would select the county of interest on the main page — it’s a clickable link.
The screen below shows my family database entry for Claus Clausen, my 5th great grandfather. Possible censuses available — not all are complete, nor all applicable for Slesvig-Holsten — are shown in the red boxes. The green box means I have attached the 1803 census to Claus Clausen’s record. (Clearly, as always with genealogy, I worked backwards to get to this point.)
This screen shot shows all of Claus Clausen’s children as of the 1803 census. If there were more, I won’t find them on the census, as the next available census is from 1835. Anna Christina Johannsen is highlighted. Johannsen is Anna’s married name.
For those records which are pre-transcribed, the screen looks like this. You do a typical search, filtering in what you know of your ancestor including first name, last name, age, county, administrative region and parish. Below is Claus Clausen’s household in 1803. They lived in Wees, within the Munkbrarup parish, in Flensbourg, in Slesvig-Holsten. (Note that at the bottom is a reference to the Danish Archives online where the original record came from.)
A Google Maps search of Wees, Germany shows the general location.
Grundhof (3 miles from the sea) and Dollerup, highlighted, are the hometown villages for another ancestral line.
The red pin below denotes Wees. The black line just to the left represents the Denmark / Germany border. The bays and fjords near Wees are part of the Baltic Sea. The city of Hamburg, which was the emigration point for my ancestors, is well south of this land area.
A useful link for Danish censuses is: https://www.familysearch.org/wiki/en/Denmark_Census , which includes links to the transcribed censuses on MyHeritage.com
I have also used Arbeitskreis Volkszahl-Register (http://www.akvz.de/index.html) in the past, but am currently struggling to properly query records which I have screen prints for, so something has changed in the past 2 years. This group, too, is transcribing census and other records stored in Schleswig-Holstein archives in Germany.
What’s been most fascinating to me is to discover the names of the towns and parishes where my ancestors came from; I suppose the next step is to comb through church records, if available online.
 Wikipedia contributors, “History of Schleswig-Holstein,” Wikipedia, The Free Encyclopedia, rev. 4 Nov 2019;
(https://en.wikipedia.org/wiki/History_of_Schleswig-Holstein : accessed December 23, 2019).
 “Denmark Census, 1845,” database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QLRV-3XYS : 23 Dec 2019), Johann Carl Thomsen in entry for Hans Scholott, Danmark; from “Denmark Census, 1845,” database and images, MyHeritage ( https://www.myheritage.com : 2016), film s00002; citing household 000275750, Rigsarkivet, København (The Danish National Archives), Copenhagen; FHL microfilm.
 “Denmark Census, 1855,” database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QLD3-DZWV : 23 Dec 2019), Peter Nicolai Holst, Flensborg, Slesvig, Danmark; from “Denmark Census, 1855,” database and images, MyHeritage ( https://www.myheritage.com : 2016), film s00003; citing household 00000343271, Rigsarkivet, København (The Danish National Archives), Copenhagen; FHL microfilm.