Of course, if you don't learn to discriminate among the signals, you will send and receive all (ALL) of the Cosmos and your signal will be greatly diluted and so weak it will be ineffective at all but the super nova signals and all you will receive is noise. You will need to focus your signal similar to the way a radio works. There are many stations broadcasting and if you try to receive all of them at once, you will just get noise. That's what most people do and why they don't believe in all the Extra Sensory Perception methods. Tune in, Turn on, Drop out. That's a pretty good formula for hooking on to energy or receiving and sending signals you are interested in.
Tune in to the signal or energy frequency you want. You do this first within yourself, then open to the outside signals. Now that you have the station, so to speak, you need to turn on your energy system to send and receive at the best possible energy. This is what many of the Tantric rituals are for, increasing your energy levels. Once you have received the energy you wish or sent your messages, drop out of the Cosmic energy field before you become overloaded with energy and harm is done. It takes a lot of practice to reach into higher and higher energy. Too much and practicioners come to harm. Too little and very little is produced. You must give to receive, meaning that your energy must be at high levels to receive at high levels. It is also important that you be on the correct frequency. If you want classical music, a jazz station or talk station won't get it. You must tune to the frequency of the classical music station. What ever you want, it's there. Just go and get it.
Be certain to ground yourself. The most common mistake beginners (or experts, for that matter) make is to forget to ground the energy so it FLOWS through you. All goes well for a bit but pretty soon, there is too much energy and you will be in trouble sooner than you can believe. Keep grounded and be ready to drop out of the energy fields any time you feel "heavy" or "floaty" or, well, we don't really have words for this. You'll learn when the energy is too strong. Try not to learn the hard way. It's kind of like sailing. If you think the wind is strong enough that you'll have to take in the sails soon, you are already too late. I can't begin to tell you how many times I've had people tell me, "I looked at the sail and said gee I'm gonna have to take that in pretty soon and then there was a BANG and the sail ripped to shreds." At the first sign of being uncomfortable, pull out, drop out, ground out and STOP.
How do you find the frequency you want? Just like the radio (again) you must put YOUR receiver on the station you want until you get the "music" you are after and then turn up the receiver to the volume (energy level) you wish to receive. For example, if you want to meditate on a tree, you must focus on the tree, relax into the shape, color, energy field, and feeling of the tree. When the tree begins to come into reception, carefully and slowly turn up the reception by "falling into" the tree energy. You will begin to perceive with the tree's senses, sensing sun, wind, insects, and one that will surprise you, the fact that the "head" of the tree is at or just under the ground where the roots and trunk meet. You will find that the tree is aware of the world about it in a very interesting way. To reach another person, place, or idea field, for example, you do much the same, focussing on the person, place, or idea field you want to access. Remember, your radio must tune to the channel or energy frequency in order to pick up any thing coherent. Otherwise, you just get noise.
This technique is the basis of most of the novice and intermediate rituals of Tantra. It is suggested you make up your own rituals. However, if you want examples and some ready made rituals, you can buy the ones on this site. We would make them free but they're pretty sexy and the world is very anti-sex at the moment. They're cheap and really work, try them.