My advice is much simpler than that:
SELL ALL YOUR GPU NOW!!
Hehe ehhe he
I think you are too late with your advice. In my country, prices for some video cards fell by 50% in 3 months
In my country video cards are still selling for 20-30% above MSRP. There are plenty of used gaming buyers on the market. This is far better than selling for half of MSRP after PoS. It's very unlikely that we will make enough mining profit in the next 3-4 months to compensate for the crash in GPU price.
Personally I'm not going to sell my rigs, regardless of the value, because I need them for software development and I can make 60-80% more profit per card than the rest of the market.