This spell is for when you want to make a positive change in yourself, whether you want to create new helpful habits, become more organized, more responsible, more attractive to the opposite sex, more tolerant, more patient, more appealing to customers, easier for your students to understand, more memorable to casting agents, more creative… well, you get the picture. It's about growing positive aspects in YOU.

You will need:
A wall mirror of decent size. You should be able to see your whole face in it.
Paint, Stickers, etc (optional) to decorate the mirror according to your intent.
A pouch to put herbs and crystals in.
Crystals, essential oils, herbs and other symbols of your intent to go into your mojo bag. (Check out Witchipedia's Correspondence Tables to select these.)
Materials for a general ritual (incense, holy water, candles, etc.)

Begin on a new moon.
Gather all your ingredients together in your ritual space.
Cleanse your space using your usual means.
Sanctify the space using your usual means.
Call the quarters using your usual means.
Call upon your personal Gods to witness your rite and present them with an offering.
List off your positive qualities and what they have gained you in your life. Give thanks to the Gods and yourself for these.

Now state what quality you wish to engender into your being and your reasons for this. Continue to meditate deeply upon this as you work.

Take up the wall mirror and carefully cleanse it using seawater, holy water or moon water. Wipe it dry with a clean cloth.
Now smudge the mirror with your incense.
Declare that the purpose of this mirror is to reflect your goal into your being.
You may paint the frame in a color that represents your desire, or paint images right on the glass around the edges where they won't obscure your face when you look into it. You may wish to use stickers for this (check the scrapbooking section of your local craft store).
Now set aside the mirror to let it dry.

Take up your pouch and cleanse it using your sacred water and incense smoke as usual.
Declare that its purpose is to hold magical items that will assist you in your goal.
As you place each herb, crystal or symbol into the bag, purify it with smoke and water and declare its purpose.
Finally tie the bag shut.

You are now ready to hang your mirror, assuming your paint is reasonably dry.

If you haven't already, put the nail or bracket into the wall to hold your mirror.
Hang the bag by its tie from the bracket and place the mirror over it.

Now take a deep breath, ground and center - balance the elements within you and look deep into your own eyes in the mirror's reflection and say "Mirror mirror on the wall I am the most __ of all!" Then give yourself a big confident smile!

You will repeat this last bit every morning when you get up and every night before you go to bed for as long as you feel it is necessary.

Now give your Gods one more offering in thanks for their assistance and thank them in advance for the new confidence/patience/beauty/charisma, etc. they are helping you give yourself.
Thank yourself as well.
Thank any additional spirits you may have involved, including the spirits of any herbs or crystals you have used.

Close the ceremony as you normally do as prescribed by your own tradition.

Variation

If you don't have room to hang a wall mirror, or can't find one that strikes your fancy, you may use a hand mirror. Tie your magical sachet to the handle using a ribbon that coordinates with your desire.

If you prefer yet a different option, consider a tray mirror and instead of placing your magical items in a pouch, just scatter them across the mirror (make sure you do not put anything else on this tray!) and move them to the edges when it comes time to look into it each day.