>>1458749Britanon here, so have had plenty of experience pitching shelters in the rain. I prefer pyramid style tents/tarps. Super easy and quick to pitch without sacrificing any protection or stability. It's a case of pegging out four corners and then using my trekking poles to raise the centre. I use just the tarp then something like tyvek or polycro as a floor. Once your shelter is pitched you get in and can slowly change while unfolding your groundsheet.
You want to avoid any shelter that requires you to pitch an inner first. My preferred mid is MLDs solomid. See
>>1458865 for an image of the silnylon version. Many me is made of DCF.