Holy water can be very helpful, so here's how you make it.

Materials:
1 tsp of Rose Water (optional)
3 tbsp sea salt or Kosher salt
1 small bowl of spring water*
1 clean glass container
1 new compact mirror
1 storage bottle (small)

* Note: Spring water is extremely hard to come by. You may not be able
to trust the bottled water, as it had been determined that many who
use it are victims of false advertising, so be sure you are familiar
with the spring water company. I suggest going on a small hiking trip
with a large glass jar (like the type you buy family-size fruit in),
and filling your jar from a running stream or other "live" body of
water that is well known for "good fishing."

Cleanse and sterilize the bowl and glass container with boiling water.
Insure that you have total privacy during preparation.
Time: Midnight during a Full Moon phase.
Place: Out of doors under the moon, or near a window that will reflect
the light of the moon.
Set out your work cloth and all ingredients upon it.
Take five or six deep breaths to relieve the stress of the day.
Cast your magick circle. Hold your arms outstreched in the Goddess
position (arms out at the sides like you are cradling the Universe,
palms up.) Say:

In the cloak of the midnight hour
I call upon the Ancient Power
I seek the presence of the Lady and Lord
To bless this water that I will pour.

At this point, you should feel the energy of Earth Mother and
Skyfather move about your feet and head. Feel your own energy expand
around your navel and then unite with Divinity. Take your time; no
need to rush.

Add the rose water to the spring water. Pick up the bowl of water,
hold it toward the light of the moon, and say:

In my hands I hold the essence of the Gods. I hereby cleanse and
consecrate this water to Divinity that it may be used for positive
acts only and may aid me in my magickal work.

Feel the energy of the Moon Goddess pulsate down into the water.
Imagine her silver light descending from the heavens and impregnating
both the water and yourself. You will feel a "glowy" sensation.

Set the water down and picl up the salt. Feel the power moving in your
arms as you raise the salt toward the moon. Say:

In my hands I hold the essence of Earth Mother; she whose bounty
sustains all living creatures. I hereby consecrate this salt to
Divinity that it may be used for positive acts only and may aid me in
my magickal work.

As with the water, imagine the energy of the Moon Goddess empowering
the salt.

Set the salt down and pour a little into the bowl of water, and stir
clockwise three times. Repeat this process twice more.

With the bowl in your left hand (recieving) and the mirror in your
right (sending), reflect the light of the moon off the mirror and into
the bowl. After a few moments say:

This liquid is now pure and dedicated to the Lord and Lady. It is free
from all negativity in any time and any space.

Set the bowl and mirror down and hold out both of your hands, palms
down, over (not touching) the bowl, about one inch above the water.

Let the vibrations of your body come alive. Open your third eye chakra
and imagine a glowing purple light emanating from it. Form and open
triangle with your hands over the water and project the light into it.
In your mind, see the water change color and glow. Feel the power and
energy flow from your head down through your arms and up from your
feet and out from your arms simultaneously. When you feel the energy
begin to dissipate, slowly lower your hands and say:

As I will
So mote it be
With the free will of all
And harm to none
This formula is done!

You may ground your energy in two ways. Either place your hands
physically upon the ground and feel the energy drain into Earth
Mother, or imagine your energy as a force field around you, and
quietly step back out of the skeleton of energy and watch it collapse
in upon itself and melt into the ground.

Transfer the water to your storage container and store it away until
you are ready to cleanse and concencrate your sacred space. Be sure to
clean up after yourself by putting all things away in their designated
places so that you will be able to find them again next when they're
needed.

-Written by Silver RavenWolf

I have also read somewhere that rain water (not run off) is holy water. I have some in a tight jar that I caught by leaving a large stanless steel or glass bowl out (not under a tree or anything). And I think you shouldn't use plastic to catch it.
Wow....I need to put some bowls out. We have had rain for several days and mor today.

That's really useful info - thank you!

I just remembered about the rain water...it is more powerful if you can catch it when it is lightening.

Magnolia gave us some info on making holy water to protect the homes from demons.

How do you make rose water?

I use ocean water gathered during or right before the full moon as Holy Water and store it in a Mason Jar. I just kinda made that up though, so I'm not sure if others would see that as correct, that's just what I felt would be best for me

You can also use rose oil to make the rose water.