Standard stuff, mostly. Mineral spirits and high quality silcone caulk (or calk...same word, different spelling.) About 10:1 mineral spirits:calk. Stretch it out and do both sides working it in well. Not a real heavy coat after it it worked in, it adds about .4oz per yard...more is probably overkill and cause peeling.
I did a plain old wind breaker. Inside, then propped it open with some sticks and outside. This was untreated fabric, though. If you start with silnylon or the like, then a light coat, say about 20:1, should work. Frankly, DWR never worked all that well in storms for me. I get about 6 hours of fairly dry time, then it starts wetting out. A fully waterproof jacket does as well, but it wets out from the inside, due to sweat in about 6 hours. Soo, generally, I don't use any. Just quick drying clothing in summer. Later in fall, I use it, though. Hiking cold means I don't perspire much. Better to be cool all day than wet at camp and at night. Often, a light T shirt and rain jacket is all I use for temps down to about 35-40F. 50F it gets too warm, so I just use a nylon or poly long sleeved shirt. They will dry in about 15-20 minutes after a rain. Again, this means hiking a bit cool, allowing my exertion to regulate my heat. Faster/harder if I feel cold. But, this is mostly solo hiking for me the past few years. Shivering cold is OK as long as you recognize the danger of loosing energy and going into hypothermia. At that point I add something else to get wet. Wet clothing is far better than no clothing. Keep your cloths ON, even if they are soaked, untill you can get them off and change in a dry area.