if you want anywhere on oxford street other than oxford circus, change buses at hyde park corner on to a 390, which runs the full length of oxford street from marble arch to tottenham court road.
Thanks mushroom, I was going to get the 22 at Putney Bridge, which I usually do …. however! I have just discovered the 74 goes from Putney Bridge to Portman Square which will be much easier, I can just walk through to St Christopher’s Place. Thanks all!!