I have begun the planning for my trip. I have watched quite a few videos of people's success in completing the walk - they have been helpful as it helps one get to know something of the terrain and possible weather!
It is also helpful seeing someone's failure, and honest appraisal for the reasons. RoguePixel mentions three in particular on her first attempt. She is right to highlight the need for looking after one's feet. I will be using boots I walk in almost every day, and in which I did my week's walking in the Dolomites last June. I learnt a lot about blister control and pacing oneself on the circumstances ahead. I have invested in some new merino wool liner socks, so will give them a thorough test before packing.
Her second mistake was in relation to the weight of her pack and her fitness. I am slowly working on building up distance walked, and with running as well I am optimistic I will be ok on this. However, I would like to enjoy the walking as much as possible. I am re-using as much kit as I can from previous walking and camping trips, but have bought some new items as, even though I will only be walking with my day pack, there is no point getting soaking wet for the whole time.
She points out mistakes in the route planning, both getting lost at one stage (thereby vastly increasing the day's milage) but also in setting oneself hopelessly optimistic targets for each day. I will have set destinations for each day rather than relying on wild camping, so I will need to be careful about some of the required distance on the rockier paths alongside Loch Lomond, for example.
I will watch her second "fail" video with interest. Was thrilled she completed it on her third attempt.
There is an important additional piece of planning for me. I am reading Belden Lane's Backpacking with the Saints and have a stack of further books to get through as I will be trying to tie my experience of walking in with some studying for my MA.