Some general tips and advice
Take a lot of interest in your appearance and wardrobe.
Practice putting your material over using gesture. Some gestures help get the information across. Watch pieces to camera (PTCs). Notice what the size of camera-frame allows. Be careful about bringing your hands into close contact with your face – not usually a good idea. Television allows for fewer nuances than radio, and so some think it a more superficial medium. The script needs to be simple and direct – subtleties are sometimes lost.
Get your audience’s attention from the start. You can hang a PTC on a flourishing turn of phrase. Energise on camera. Think about your on-screen persona. One presenter describes himself as having ‘a beam of low-key goodwill’; as being ‘seraphic, equable and affable’.
Rehearse your script out loud to see how it sounds. Think about taking the viewers through your text at a pace, and with a logical structure they are going to understand.