Step1
Look around and find a friend or family member with kids (preferably all boys). Then ask if you can come over.
Step2
Silently observe their kids as they play with their toy cars or my little ponies or what have you. Make a list of all the different types of sounds they use and how often.
Step3
Now go outside and walk around for a few minutes. Again, make a list of all the sounds you hear around you (breaks squealing, horns honking, birds chirping, cell phones ringing, or the rumble of skateboard wheels on pavement)
Step4
Go home and try to mimic those sounds with your spouse and/or children. What fun it will be! Start by smacking your lips repeatedly and wiggling your tongue. Then puff out, stretch, pull, and tweak your cheeks. These proper pre-sound effect warm-ups will prove helpful.
Step5
Start with a car. For now any old car will do. Remember "Vroom?" Well, it's the same thing, but with out the "room" part. form your mouth as if you were about to say a word that starts with the letter "v." Now begin to say that word, but cut it off at the v-sound and hold the sound out as long as you can.
Now take one of your son's toy cars and drive it across the carpet while you make this same sound.
Step6
To increase the car's speed, simply increase the volume. To decrease its speed, lower the volume.
Let's switch gears, now. Make that same v-sound, increasing the speed, until sufficiently loud, or laboring. Then pause (briefly) and immediately make that same v-sound again, getting louder and louder after each time you "shift."
Step7
To peel out or slam on the breaks, form your mouth as if to say "urks!." Now say it, but leave off the "k" and raise your voice to your upper register, or falsetto voice. Now hold that "ur" sound out as long as you can.
if you wanted to make the sound of metal bending, simply slow this down. Change how high your voice is to signal the speed with which the metal is bending. Low = slow. High = Fast
Step8
The explosion. If you have ever had a cold and had to clear your throat of phlegm, this should be a piece of cake.
Simply form your mouth as if to say the letter 'P' as in "pug". Then say it, almost instantly adding the guttural rumble that comes naturally with bringing that mucus up from the back of your throat and into your mouth.
Shorten the process for quick explosions or elongate the process for larger ones. To create "The Big One," add a "Sssss" sound (like a snake) and follow it up with 2 to 3 small explosions followed by a large one.
Step9
Now that we have cars down, let's look at that pony. To do this, smack your lips again to get them as loose as possible. Then extend then extend them out (like an exaggerated kiss), but keep the overall shape of your mouth flat. Now, press the inner portion of your lips together while relaxing the actual lip itself.
Step10
Now blow air out your mouth, keeping your lips in the position above. (This sound is better suited for planes, lawnmowers, and that old Model-T.)
To add life to it, make the sound again, but this time as you do shake your head from side to side as fast as you can and naturally let the sound fade off. And there you have it!
As you increase the rate at which you blow air out, you will find your horse's attitude changes, from happy (with little air) to frustrated (with lots of air).
Step11
If you want that horse to walk about, use your tongue to click the roof of your mouth.
Step12
You are now ready for the final step. You have to test it out. Schedule a time to go over to your friend's house again. Make sure their kids are playing then ask if you can join in. They will be hesitant at first, for sure.
Step13
Choose any old car (the junkier the better, since their expectations will be low) then nonchalantly start her up and take off down the road in 1st gear. Keep it in 1st gear for a bit as if you were taking in the countryside, until you notice them starting to watch you with interest.
As soon as they do, shift into second, then 3rd, or skip straight to 4th and 5th. Peel out down the road, zipping around the countryside corners with reckless abandon. Make sure to squeal those breaks on the corners.
Step14
When the kids put down their own cars and My Little Ponies, you will know it is your big chance. You and they are ready for "the Big One!" Grab the unsuspecting pony and have it waltz down the road. As the car turns its final corner, slam on the breaks. The horse bucks into the air, breathing an angry warning.
"Get out of the way! She's going to blow!" ...Airy snake sound, followed by two short explosions, followed by a larger one then an even louder and longer one, then again and again and again. Your voice fades as the fire dies down.