The last time it it $1K, I didn't sell any of my coins. I thought it might go all the way up to $10K. It Iwas such a shitty decision. However, if it hits the $1K mark once again, I am offloading half of my coins. 
Same, although I didn't think it would hit 10k,more like 2 or 3k.
BUT, I think if there's another bubble soon, it could easily get to those 2-3k levels, simply because a shitload more people know about Bitcoin this time around...
I would probably sell a couple of coins at 1k, a couple more at 2k, maybe a few more at 3k. Then HODL!