high + low
→ everywhere, all over the places
I searched high and low for my glasses, but I couldn’t find them anywhere.
spick + span
→ very very clean
Your house always spick and spam. How do you do it ?
thick and thin
→ many good times and bad times, all kind of experiences
They have been married over 15 years and have been through thick and thin.
touch + go
→ uncertain, a little bit risky
His condition is still touch and go.
leaps + bounds
→ a lot, trimendously
Your English has improved leaps and bounds.
now + then
→ not very often, infrequently
We only see each other now and then.