Ugh that's such an easy mistake to make. I started using a simple ruler on screen to check the actual printed size before sending anything to print. It forces you to see the real dimensions instead of just how it looks on your big monitor. Made a huge difference for me because I was doing the same thing. Now I have a little checklist that includes minimum logo size before any project is finished.
Yeah that checklist idea is smart. I started putting a physical ruler right on my desk as a constant reminder. It really helps to see the real size instead of just trusting the screen.