PROJECTING YOUR VOICE
Use your Breath not your Throat
Many singers (and speakers) instinctively squeeze the muscles around their vocal folds when they want more volume - but those muscles are completely unnecessary for this task and even can inhibit the very thing you are trying to accomplish. Try this: keeping your throat, neck, shoulders and jaw very relaxed, say "Yeah!"; then say it again, gradually increasing volume, while at the same time staying in that relaxed position. This way, instead of squeezing to get volume, you are training your body to use a comfortable resistance of air to achieve it. It will take a period of focus and mindfulness to retrain your nervous system but eventually this more relaxed approach will take over as your new muscle memory.
Aim further than the microphone
Sometimes a new student will come to my studio and, after taking them through some vocal exercises, I'll ask them if they are used to singing with a microphone. This is because I will have observed that they only project their voice about two inches in front of their face - only aiming as far as a microphone. Mentally aiming your vocals towards your audience, or even a point at the back of the room, instantly changes how far your voice is projecting (and also helps your audio technician prevent mic feedback).
Enunciate (pronounce your consonants)
While singing mostly involves holding notes on the vowels, consonants are, of course, also important. Singers often don't notice that they are under-pronouncing their consonants and even feel uncomfortable when asked to do so. When I've demonstrated this idea on a student in a workshop and had them "over do" their consonants, the consensus for the rest of the listeners is that it sounds just right (note: the degree to which you "over do" your consonants will often depend on your genre of music). It can feel strange to emphasize your consonants when you first try it but, after awhile, it will start to become your new normal.
Vocal Acoustics (drop your jaw)
Sound waves and harmonics play a big part in projecting the voice. If you've ever sung in the shower and enjoyed the way your voice bounced off the smooth tiled walls you'll understand that different acoustic spaces can change the range of harmonics that hit the eardrum. By adjusting your vocal acoustic spaces in your mouth and throat you can "aim" those sound waves so that the listener perceives a louder sound. Dropping your jaw is a simple technique that allows an additional range of harmonics to reach the listener's ear, without actually singing "louder".