I use TUBEPAD, which is based onUsoft paint with symbol [both US and RSGB] and component outline libraries. Good free QD [quick and dirty] software
https://www.qsl.net/wd4nka/TEXTS/Tubepadf.html
"Welcome to the TubePad Web page.
TubePad is not a program, firstly. It is a series, or library of images. These images can be called upon by any image viewer, although TubePad was written (drawn) on and for MS Paint. Because there is no execution file, there is nothing to run but your own on-board .bmp IDE. This makes for an extremely safe, non-invasive, and easy to use system of creating decent looking schematics and design illustrations for hobby, web-design, educational, and whatever other use one might think up"
Abbreviations
fd should never be used for Farads, only F; the unit 1st letter is a capital and so is the abbreviation - e.g. 0.01µF. Occasionally you see mfd [µF] and mmfd [pF] in USA history, but this was unclear; mfd should only mean millifarad [i.e. 1000µF] and there weren't too many of those around back then.
same goes for Volts [V], Henries [H], etc