1) A voice that can transmit emotion
Ok so it’s all well and good having a nice voice, but that is not enough, you need to be able to act, yes even though no one will see you. When you act out these scripts it helps to transmit the emotion. Acting also helps to provide the right emphasis and right inflections that the script that might be needed.
As a voiceover you need to be able to take direction from the client, studio engineer or the direction given by Skype. It is not wise to try to do your own thing because you think that your style or way is much better. You are paid to be a voice on the project not the brains
3) Home studio, good microphone and software
Ok so recording on your mobile phone is great for practice but not good enough quality for professional jobs for sure. You need to be able to soundproof the room or side of the room you are using to do recordings. There are many acoustic tiles and foam you can buy online to do the trick. If you are not a DIY person than there are portable sound booths online to buy too have a look at Harland Hogan. Amazon and EBay too. Some good software to record and edit your voice samples is audacity, pro tools and Garage, there are many so have a look at what suits your budget.