We recommend obtaining and inserting your graphics in a vector format (SVG, EMF, WMF or alike). You can create good looking diagrams online on sites like
Lucid,
Draw.io and download them in SVG format (importable in Word) or high quality PNG (zoom in and then export the drawing in the current scale). Or use the free Inkscape application, or another vector graphics tool. If you cannot get the images in vector format, consider:
- saving your screenshots and images only as PNG, instead of JPG
- if you are using Word, then Word > File > Options > Advanced > Image Size and Quality > Do not compress images in file, and then insert the images into your document
- when creating the PDF, disable image downsampling, also disable image compression or at least use ZIP compression, "lossless" compression, or JPEG2000 compression on "maximum" quality.
After you inserted the image into the Word document, you can crop it (pull its margins inwards to hide some parts, or pull them outwards to leave more space around the image or show parts of the image that are otherwise hidden, due to importing artifacts:
Word > click on the picture > Picture Format > Size > Crop).