Last time use Xymol which I think it's a good product as it soften leather

Then I found another cheaper alternative which is coconut oil.

Clean leather first, then after dry apply coconut oil.
I bought some oil in sachets, basically apply on all cushion use 2sachets
Can do it every month also and your leather will feel very soft

apply thin layer.
leave it for 30min, then use dry cloth and wipe of excess. then leave it for 12hrs or so. (need sometime for the oil to absorb in)
apply too thick it cant dry.

next day cushion will feel very smooth and soft
usually i'll apply at night