A few things I wish I'd known studying for the CCNA, from someone who does it for a living
I work in networking (CCNP) and spend a lot of time around people prepping for the CCNA, so a few things that tend to save people time:
Learn subnetting until you can do it in your head, not on paper. The magic-number method (256 minus the mask octet) gets you the block size, and from there the network, broadcast, and host range fall out in a few seconds. On the clock, that speed is worth real points.
Don't just memorize, understand the why. A big chunk of the exam is symptom to cause, not recall. If you know what a feature actually does, you can reason out a troubleshooting question even when the wording is unfamiliar. Pure flashcard memorizers get wrecked by those.
Spend real time in a simulator. Packet Tracer is free. Actually configuring VLANs, a trunk, OSPF, and an ACL teaches you more than reading about them ever will, and the muscle memory shows up on config questions.
Space it out. Twenty focused minutes daily beats a five-hour weekend cram. The blueprint is wide, and spaced repetition is what makes it stick.
What tripped the rest of you up the most? Curious what people are stuck on right now.