For realistic checkpoints I recommend using it on the whole range depending on the desire outcome but the default value is 0.7 where it works great.
I also recommend using it on negative -1 to create a less realistic image.
For non realistic I recommend not going above 1.00 strength
The model has the following tags:
MassiveNaturals
*activates the whole LoRA
Natural breast
*Gives a more natural look, The model also has other breast that don´t suit this category.
Firm breast
*Makes breast more firm
Saggy breast
*Makes breast more saggy and incrementing the strength will make MILFS
lactation
*Will make the breast look full and also shinny, it could also help create self sucking breast images.
Hard nipples
*Will make nipples hard
Soft nipples
*Will make nipples soft