I know what you're thinking. I just have a really smart, gifted baby. Well, no. Over the years, I've had my bubble of pride burst again and again, realizing that my child is just an average kiddo like everyone else. What makes the difference is training. After reading some child training books when my son was just a newborn, I got the idea that if I can train him not to touch dangerous things, or crawl up a flight of steps, and to pick up his toys when he's through, certainly I can teach him how to hold a spoon and feed himself without making a mess. So when he was old enough to sit up on his own, hold an object and eat solid foods, which was for Marek around 7 months, I started training him to feed himself.
It is really quite easy. First, make sure your baby can sit up on their own, hold an object, and can eat solid food like baby cereal or pureed fruits and veggies. Next, set baby up in the highchair and sit in front of him. Place the spoon in his hand with your hand over his. Direct his hand to scoop up the food in his dish and bring it to his mouth. At first this will be a new exercise and baby may decide not to co-operate, but I found in teaching all my children this same way, that as soon as the food gets into their mouths, they're more than willing to play this "new game". An important extra step for you, mom, is to smile and encourage a lot every time your baby complies with each new command.
Continue the same motion of scooping the food hand over hand and bringing it to baby's mouth over and over until he understands the movement and can do it on his own. This will take a few days. When baby understands how to operate the spoon on his own, you can then take your hand off, but keep it nearby, ready to catch any wayward movements and redirect the hand back to position. It will just be a matter of time before your child will test his boundaries and try to fling food or a dish across the room or attempt to dress himself in it. When this happens, you must firmly tell baby "No" and show him again, hand over hand, the correct way to hold and operate the spoon.
Now, your children are very smart and they will know what is expected of them, so keep up the training and do not give up! Remember, the moment you stop training is the moment you have taught your child that they are in control and that is extremely disastrous! So keep working faithfully, hand over hand at every meal, every day until your child fully understands how to eat properly. Then, wherever you may be, mealtimes will be a refreshing time to enjoy your food and family!