This may be a little ‘OCD’ but I pack all my kit for each day in advance in separate bags so you can easily get them out when you arrive in your hotel without having to unpack your overnight bag completely.
As the weather between London & Paris can be very changeable, even in July, you will need a gilet, rain jacket, arm warmers, key warmers and even maybe overshoes. As we tend to roll early in the morning when it is a little chillier I would recommend wearing more layers in the morning and carrying your rain jacket, which you can then discard at lunchtime and put in your in your day bag (you’ll receive a ‘musette’ for this at Sign On).
On the subject of weather, you should also make sure you have your sunglasses, sun cream and mits for the sunshine all the way to Paris … I would also pack your waterproof gear (rain jacket and overshoes) and winter gloves, just in case the weather turns against us!
Obviously, you must not forget your cycling shoes & helmet … I know this sounds obvious but if you drop your bike off at Imber Court during sign-on the on the Wednesday before our Grand Depart, it is easy to turn up on Thursday morning with your trainers on and no cycling shoes!!
On the subject of footwear, it is a good idea to have a spare pair of socks, your trainers or flip flops in your musette, so that at the end of each day in the saddle (and in your cycling shoes) you have something to slip on for the short bus ride to your hotel. Spare socks are also helpful, in the case where we have a wet morning you can at least put some dry ones on at lunchtime.
You should also have a fresh top to slip on for the journey to make sure you do not get cold in transit. This is especially important on Day 1, where you would benefit from a set of fresh and warm clothes in your musette for the journey across the Channel, as well as of course your passport!