It’s quite difficult to practise your public speaking. You can practice your words, but speaking to the mirror or the dog is not the same as being in front of an audience. (I’ve omitted friends and family, who are always too kind to be objective.)
Observing other public speakers can help you improve your own skills; copying what’s best about them and disregarding the rest. Politicians are nearly always good public speakers in the flesh, but television performances don’t count as they are over-trained for this medium. Councillors are also worth watching as the more experienced ones are used to addressing public meetings. Also, don’t turn down watching a bad public speaker – what not to do is as good guide as what is.