Firstly, welcome, Lord1B, to FlyerTalk!
This first post of this thread gives you great tips, and ways to achieve £1/TP. I haven't been on anything that sophisticated myself, however I believe that HNL and the west coast often produce the best tier point yields.
Unfortunately, mid-July is peak season; when all the parents and children go on holiday and boarding school kids go back home. Fares can often get quite expensive, however this isn't always the case. European runs such as AGP, TLL (although not as good it was before), and destinations such as Helsinki (and further) can provide a good return depending on sale fares ex-UK.
A personal tip from me is: do you want a holiday/vacation as well or are you doing it purely for the TPs? If you want a holiday out of it, perhaps split it up into two holidays (which is what I tend to do) but sacrifice the £/TP ratio. Otherwise, be flexible and adapt to ludicrous turnarounds/flights etc.