Thin blue smoke

I live at 4600 feet and i am curious as to how to achieve TBS on my mini wsm. If i put the wood chunks on the pile of lit coals, it usually produces thick white smoke. I only use maybe 2 chunks at the most and they are small size, IE, 2 inch by 1/2 inch. However, it may be because i have to much lit to unlit. That leads to my second question. I have read my other post here regarding the lit to unlit but im curious to how many of you have heard of the 15% rule?

I was told at one time, i use light 15% worth of the total unlit charcoal you are using in the fire basket. IE, 150 unlit to 20 lit(ithink thats15%) or is it best to put the wood on a grate above the fire?

thanks