One thing that seems to get neglected when people make conscripts is the detailed history that most writing systems go through—with the exception of borderline-conscripts like Cree Syllabics, the most-used systems tend to have huge histories, sometimes spanning thousands of years of revisions and changes. All real-world scripts are equally welcome on this page!
Abbreviations and Shorthand
PDF of the characters in Vernon Kooy's Renaissance Greek Ligatures font: particularly noteworthy; the source text for many of the abbreviations seems to be grammatically- or rhetorically-focused. Here's the site and here's the font itself.
Karl Eberhard Henke's guide on Tironian notes (c. 1960): the only complete one I know of; it dates to the 60s. (If you're interested in shorthand in general, you may also appreciate Towndrow 1835 or Pitman 1857.)
The elements of abbreviation in medieval Latin paleography by Adriano Cappelli (1929, trans. 1982 by David Heimann & Richard Kay): pretty comprehensive, and actually includes depictions of each abbreviation, unlike a lot of other sources which merely describe them.
History of Scripts
Medieval Writing showcases a number of different scripts from Western Europe, although almost all of the samples are very low quality. (It's pretty old.)
The Greek Font Society has a number of nice fonts, mostly Byzantine majuscules (often epigraphic).
Fonts for Latin Paleography, adding on the recommendation of Legion.