This is what I do, scent-wise to hold on to the summer feeling for a few more days. Nothing advanced. But it works for me so it might work for you too!
- I drink a lot of infusions made from fresh summer herbs. I love a cup of tea and a blanket in the autumn but the earl grey also gives me a november feeling. So my summer version is to use fresh rosemary or verbena leaves and some honey or cocoa sugar. Not only does it taste great, the smell is fresh and uplifting. But try to find fresh ones, you need the right-now-ness, dried will be like "remembering".
- The summery perfumes... There are a few safe classics that inevitably sing olfactory arias about sand and sandals to your brain... Neroli di Portofino and Bronze Goddess are two of the most well-known. For a more discrete effect I like to use what is left of sun screen lotions from the summer. Somehow there always seems to be an amount enough for 2-3 weeks more left. Using these lotions as moisturizer (which post-summer office-schocked skin really needs!) gives a soft scent of summer that stays close to the skin. Be careful however when you wear summer/vacation scents at work since that is also the feeling that you will send out to people around you - so don't smell like a day on the beach for important work meetings! It is not a very authoritative or reliable signal. Use your nice medium sillage elegant fragrances for those days. But for more off-stage days, evenings and weekends - indulge in summer scents for a few more weeks!