Grimoire/BoS Seal of Protection

First draw on the first page of your Grimoire/Book of Shadows an upright pentagram of the size you feel comfortable with.

Then put enough oak bark dust in the exact middle of the pentagram so the dust covers it completely. That means that you have to try to even it out ad much as you can while still only have the dust in the center.

After that you need to hold you main hand's index finger 2-3 centimeter above the dust. If you wish you can also use your wand. Then chant:

"I ask those who want to know my secrets to stay away. I ask those who want to know my spells to keep their distance. I ask the dust from the mighty tree to protect my book till the day I remove this pentagram. I ask this, so please make this be."

If you lack the oak bark dust:  First take your mortar and pestle and put as many bark in it untill your satisfied. Then grind the bark to dust. This dust may by a fine powder or a rougher powder, whatever you feel the most comfortable with. If you have all the dust you need start with drawing the pentagram and then just continue the spell.