I can't help with tacking up western as I never have before but I sure can help with grooming.
Grooming These go in my grooming order, others may do it differently. Also, the italicized stuff I only do if I have time.
Hooves - I always pick the hooves first. Checking for stones and loose or missing shoes. I always make sure the hoof wall is nice and clean too. Also, if I am apply hoof oil I do it now so it has time to dry.
Curry - Curry the body, neck, and bum in small circles breaking up the dirt. Sometimes I use it gently on the face and legs if they are really muddy and won't come off with just a brush.
Hard Brush - Brush away all the broken up dirt on the neck, body, and bum. Again, I also use on the legs and face, carefully, if they're really dirty.
Soft Brush - Go over the whole horse with this. It gets any excess dirt off and brings out a nice shine.
Detangler - I prefer the Mane and Tail detangler or Show Sheen and spray in mane and tail before I brush it out.
Mane and Tail Comb/Brush - Brush out after you detangle with a comb or brush. Remember to always start at the bottom of the tail first and work your way up.
Extra Shine - I prefer Show Sheen or Hair Moisterizer (the Pink stuff). With the Show Sheen NEVER spray it on the saddle area because it contains silicone and makes the saddle area really slippery. Just mist over the horse and brush with soft brush again. With the face I spray it on my brush and then brush face.