Well, digital recording along with pretty dead quiet mic pres in even basic interfaces gives you a lot of room to adjust things after the fact, but -18dB doesn’t mean much by itself. Is that peak? RMS? LUFS? Eyeballed nominal? And, then what and/or who are you recording and what will you do with the tracks? An experienced session player can be dialed in tightly while your buddy from high school probably needs a little more room so the stray peaks don’t clip.
For me, recording level needs to take into account, to some degree, how many total tracks I’ll have (usually just a few) and so I try to simply keep peaks at -10dBFS plus or minus. That’s a place where I can get a “static” mix quickly with just a few gain adjustments on the tracks before messing with automation and compression, and still have plenty of room to land at a target loudness and keep the dynamic range where I’m happy.