Can you advise what to avoid in Paid Search?
We could advise many things! Avoid doing it yourself unless you are skilled, trained and qualified. Google does offer support, but remember they are the advertising platform so if you have £500 to spend they will take that and help you, however a trained person with your business interests at heart may be more focussed on efficiencies in improving conversion acquisition as opposed to simply spending budget and having great visibility!
One other caution is to ensure that if you have an existing Paid Search campaign, to obtain a full audit prior to starting to optimise results – this can make a big difference to your conversion rates and ROI.