How do I inflate a latex balloon?

A perfectly inflated latex balloon is generally shaped like a teardrop. An under-inflated balloon will look like a beach ball whereas an over-inflated balloon looks like a lightbulb. Some larger latex balloons generally larger than 24 inches may blow up rounder.

Tips to Inflate the Perfect Teardrop Latex Balloon

• Stretch the latex balloon with your hands before inflating the balloon.
• If the balloon begins to bulge, let some air out until it looks like a teardrop.
• Keep inflating the balloon if it is shaped like a beach ball– except in those cases where the balloon is meant to blow up round.
• Under-inflated balloons will be round in shape, have reduced float times, and will appear less shiny.
• Never inflate the neck of a balloon because this space is needed to tie the knot.
• Overinflated balloons have a light bulb shape and are more likely to pop because the latex is so stretched out.
• Once the body of the balloon is inflated, the air/helium will displace into the neck creating a bulge and making it more difficult to tie.
• Using a balloon sizer will always guarantee a perfectly shaped and sized balloon (eg. Slide-N-Size, Balloon Sizing Templates, balloon sizing box). 
• Under-inflated balloons are great for games that require sitting or stomping. They are challenging to pop, however, they are not visually appealing when used as decor. 

30" and 36" latex balloons from the manufacturer Qualatex's blow up to a rounder shape as shown in the image below.