Don’t put any money into shares yet.
Keep a very watchful eye on the prices by all means, but there’s going to be plenty more falling to come yet (and falling by the wayside/nationalisation depending on how big the institute is).
Some people are going to make a killing, and it’s not the ones that have a spare £100 or so right now, and fancy taking a punt, that are going to be the ones. It’s the ones that sit tight, and have many tens, or hundreds, of thousands of £’s to spare to invest at the right time.
When the construction industry kick starts again, and the housing market starts increasing in value instead of decreasing, shares in companies will rocket overnight. Then is the time to have some spare cash hanging around!