With the trade unions demanding parliamentary representation and the organisational difficulties they had after years of decline, any Liberal minority in the '20s is tricky, but doable. If Lloyd George declined the Coalition Coupon, or he calls a halt to the Passchendale offensive in 1917 as he had reservations IOTL, and the government falls. Bonar Law, or if he didn't fancy it, another Unionist would pick up the Premiership, and the Liberals reunited in Opposition.
Asquith by Stephen Koss or Bonar Law by RJQ Adams have a few PODs to work with, I can bring DM you more ideas when I'm back home.
But any Liberal minority would show off why they deserve another chance. Negotiating away trade disputes to not anger the working classes - no General Strike perhaps? Infrastructure reforms, eletricity, housing, consensual, pro-Versailles diplomacy. Investment in industry and ideas of co-ownership if they get time for it.
Renegotiating war reparations and some manner of trade agreement with Ireland seems probable.
I think post-1918 any recovery was always in question, and post-1922, permanently impossible, for structural reasons. In this last Liberal government you probably just accelerate the split in the Liberal coalition - John Simon, et al, journey to the right, while the Radicals realise how well they work with Labour.
If the Liberals can sustain working class support, I can see some in Labour pushing the radical line, gaining extractions. But with the Liberals on life support, MacDonald's Cleggism for the Twenties may very well strengthen Labour in the long run. A split when DLG refuses to renationalise the mines but makes the mine owners forfeit their royalties?
William Adamson could have been LotO in 1918 when he came ahead of the Independent Liberals, but didn't assert his claim. I think there's a lot to be said for how Labour saw themselves as independent but a prop to the Liberal movement, until suddenly they weren't.
Pipisme's TL in the Other Place is good, sidesteps the how and shows you the what.