here's what we do.
How To Raise Power For Magic
Before you speak a spell or touch anything, you need to be in the right state - you should be tingling with power.
This is easiest done in the following way:
1. Breathe deeply, through your nose as well as through your mouth.
2. Stand comfortably and get a sense of energy flowing into your through your feet, coming in with your breath, pouring into you from above.
3. Focus your mind on your power to do magic. Say to yourself and think in your mind: "My power" with every breath.
4. If you can feel any physical signs such as pains and pressures in your body or head as you do this, take some time to breathe into those ereas and make those disturbances flow away. Concentrate only on your power to do magic.
5. When you are tingling all over, bright aware and bursting with energy, feeling electric, you're ready to go.
It gets better and faster with practise; if you don't do this before you start, your spells won't run on full power.
NB There is another good energy raising exercise that is a little more advanced, Father Earth Mother Sky see here.