How much time you put in, is how much result your going to get. With some exceptions due to genetics and climate.
I would rise and blow as much as you can (no more that 3 times a day but no less than 2 times a day).
I personally wouldn't use oil during the day because it collects a lot of dust.(some would argue that the oil grabs the dust so it can't get to the skin, helping keep it clean. So go with what you think.)
I just use a sheen(clean sheen or the considerate you mix yourself with water) and mix it with absorbine Liniment (found in the horse section at our local farm store. Sullivan's also have a similar Liniment product.) You don't need too much liniment and I probably mix at a ratio 1:5. Or until sheen is a light green color. ( --> This is a website with more info and a pic of the absorbine Liniment
http://www.kyhorse.com/store/health/liniments/absorbine.htm)
The liniment helps chill the hide and helps keep bugs and fly's away.
Like others have posted I would spray in the sheen and comb in ( use rice root brush if shorter hair to help train the hair.) then use the blower to into the skin and dry it.
At night before I turn out the calf is when I put a oil in the calf. I use a light oil because a heavier oil can trap in body heat.
Some other things to keep in mind are:
1.Get your calf out of the sun or heat. Get your calf tied up early and turn out after its cooled down.
Ive heard of people turning their calves out wet in the summer months to help keep calves cool. I wouldn't do this because it can actually raise the body temp on the calf. If you feel your calf you would notice they are warm. Doing this open their pours on the skin and can be worse on the skin because it gets dust and dirt in them.
2. After rising steers at night I would tie back up under fans( in AC unit) then blow them out after standing for 1/2 hour or so. This helps close up the pours allowing them to stay cleaner. Then complete the things I stated earlier.
3. Use a roto brush on the legs but don't over do it, can pull hair out.
4. Helps to keep the same schedule, Calves seem to act better.
5. rinse down bedding night before so less dusty during the day.
If you have any other questions feel free to PM me. I got tons of little tricks but this would be a good start.