By setting alas at different times of day and pro actively reminding yourself to be grateful for many different things. This way, it becomes a mindful habit.
When I am grateful for someone, I can show them just how much by not taking them for granted and show them love. I am grateful for something, I can just sit back and reflect and how lucky I am to have it and for it to be in my life. A lot of people don't get the things they want and I have a lot of the things that I want. I'm grateful for that.
You can make the grateful habit more effective by thinking of colours. Each colour will represent something different to each individual like blue might remind you of the sky or water which in turn will trigger a happy thought like "I am grateful for clean drinking water or I am grateful for the clear blue skies today" etc. Or green might remind you of the leaves on the trees or an apple so you could be greatful for food or a nice walk through the woods. Or a colour could remind you of your favourite sport or person. Using colours is a handy tool to help you jog your memory and in turn help you reflect upon what you are greatful for. 😀 Have a nice day