@Battersea Boy - welcome and enjoy. The other members have provided wise advice.
I thought I'd share with you, as noted by
@Dansco above, that some people cannot use alum blocks, and I am one of them.
No matter how good a shave I have, the application of the alum block causes me irritation. I persevered for months, thinking it was a technique thing, but the penny finally dropped. I am also sensitive to post-shave products containing alcohol.
Aloe vera post-shave, as others have mentioned, it usually a winner. What works best for me are no-alcohol post shave products like Thayers Cucumber Witch hazel (also contains aloe vera), and Myrsol Emulsion (key ingredients glycerine and lanolin).
If I've had an absolute shocker, I use a product called Thayers Topical Pain Reliever, sometimes referred to as Superhazel. It contains a bit of alcohol, but the active ingredients soon go to work and save the day - it has never failed me yet.
But, as always, every face is different, so experiment until you find what works for you.