How to make home more energy efficient?

Hello all,

Was wanting to get some advice. Me and my wife have just had our agreement in principle yesterday (yay!) so keys hopefully in august.

I wanted to ask what I could do to make the house more energy efficient (less costly to run the house).

We’re can’t afford upgrades expensive upgrades at this stage (solar, air source heat pump etc)

In terms of what upgrades the house has had or already has : double glazing, boiler installed within last 5 years. Loft insulation

Small upgrades I can do : upgrade all bulbs to led, thick thermal curtains, invisible pelmet, drought proofing.

Does anyone else have any other recommendations?