Without anymore detail than provided there are several options to achieve the "distressed look" as I will go through several options. Most screen printers in the past have actually distressed their positives first and this entails the following:
Scratching or beating positives with chains (quite Neanderthal but it does provide a custom look).
Tinting your art with a distressed screen.
Now concerning your ink choices, soft-hand additive is chock full of plasticisers and adding 99% will not give you any softer hand. It will however totally destroy the intensity of color so here are several options.
Use a "curable reducer" note the word CURABLE, this is a body reducer that can make the ink have the same characteristics as warm syrup, very runny and it will permeate the fabric.
When using soft-hand and especially a curable reducer you'll want to go to a much higher mesh count, nothing lower than a 195 and upwards to a 250 mesh count. This coupled along with an ink that has been reduced using a curable reducer will "dye" the fabric versus just laying it on top. A sharp squeegee, 70 duro plus is recommended, for more saturation you can use a softer squeegee but your last screen should use a hard, sharp duro to drive the colors further into the fabric.
Use a halftone tint over your entire design, say starting at a 70% tint. Not my favorite way to reduce hand but you are only laying down 70% of the ink.
These tips should give you the results you seek, if there is anything else we at Ryonet may help you with please don't hesitate to contact us, thank you.