Glitter and shoving, the first advice is 'if it's safe to do so, Get out and stay out' every time. How ever if access is blocked, or for any reason you can't get out, we would advice you to go to the furthest away room from the fire, get everyone together Inc mobile, close doors behind you. Open the window in the room you are in, put towels, bedding, clothes, anything round the door to stop smoke getting in. Most internal doors these days are designed to withhold fire for at least 25 mins. Stay on the line to the operators and tell them whether you are at the front or back of building, which floor, type of property. Stay low as you can by the window. Hang a sheet or something at the window you are at. We wouldn't advice to jump unless you are imminent danger.
We had one not long back where the dad dropped his baby out the window, which we caught. Your heart races thats for sure.
However! Grenfell was unprecedented and on a scale we are not trained for routinely. Obviously we train in high rise buildings, but in them, each flat is supposed to be a 'survivable chamber' hence the stay put advice. The way that Grenfell went up was criminal.
I think the tvs should have been. On in the control room that night, so the operators had a visual on what was happens. I imagine the stay put policy may have been changed sooner. Having said that the operational firefighters and those in control did their very best. I'm rambling now! But to answer your question if it were me and my family in a high rise, I'd try to get out first. But toxic smoke can incapacitate after 5 breaths so it would have to be clear of smoke. I wouldn't risk going through smoke and hoping for the best. It's such a difficult question.
In terms of prevention, get smoke alarms and test them! Don't overload extention cables or plugs, and don't smoke if possible or start to cook food late at night if you've been drinking!