Here are step-by-step directions on how to properly solder,
Set soldering iron (see picture) and wait 4-5 minutes to heat up.
Choose solder: with lead or lead-free. The solder without lead has a higher melting point, meaning the soldering iron needs to be turned on to a higher level
Set up helping hands and layout all needed materials. Wet soldering iron sponge. Additionally turn the exhaust fan on. Tip: double check if you have all the materials needed to complete the project, you do not want to find out too late that you do not have the right materials.
Don't: Try to to breath in the solder fumes, because it often contains lead, and make sure the exhaust fan is pretty close to your work.
If soldering components to a circuit board prepare those by putting the wires in the correct way. Tip: Bend the wires so the component stays in place.
Don't: Leave components sticking out. You should make sure they are in the desired place before bending the wires.
Now hold up the circuit board using the helping hands. Tip: Make sure the circuit board is stable and the component is still in its right position.
Pick up the soldering iron with your more favorable hand in the correct fashion as shown in the picture. Hold the solder holder with 1-2 inches of solder sticking out.
Don't: Have too much solder sticking out, it will be harder to precisely apply the solder to the component.
Place the tip of the solder at the base of the component and the circuit board.
Touch the soldering iron to the solder. Burn just several centimeters off the solder. Tip: Never let the solder be too short, never shorter than the picture above.
The base of the component should look like the first image. If it looks like the second one, add a little bit more. Tip: The most important part is that the solder connects the component to the circuit board.
Carefully place the soldering iron back into the holder.
Don't: Misplace the soldering iron, it could lead to someone or something getting burned.
Take a pair of wire cutters and cut the soldered wire so there is at most 5mm of wire left.
Don't: Leave too little or too much wire left; too little could be bad if you need to desolder it then change the component's direction, too much could mean the wire gets stuck on something.