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