Insurance policies & annual plans
Always shop around when your annual insurance policies for e.g. home contents, car, pet, phone etc. come up for renewal.
Use comparison sites to find the best deal, and never just renew unquestioningly with the same provider. If you do want to stick with them, haggle for the best price they can offer - you can often use the ‘chat’ function to message an agent via their website, or call (via freephone if possible) to speak to someone.
Comparison websites include https://www.moneysupermarket.com/, https://www.gocompare.com/ and https://www.confused.com.
MoneySavingExpert also has lots of information and suggestions in their section on insurance.