A safer(?) way is to make a design similar to the jungle temple puzzle, but this time using BUD switches. When you break off specific blocks from a wall in a specific order, then put them back in a specific order, then the entrance is revealed.
Although no amount of hiding would be safe from a simple see-through texture change.
I favor the fatalist approach. If enemies finding your base and destroying it is a possibility, it will happen. So don't expend massive amounts of effort, just make it as secret as you easily can and always have a plan to start over. Nothing is perfect, and nothing lasts forever. Be ready.
Rollback Post to RevisionRollBack
"Sometimes, I just wanna give up, say 'I'm done with this mess' and go to bed. But you know what; you can't shrug off your responsibilities. You got to pull yourself up and meet the challenges head on. That's the only way you're gonna get ahead in life."