It's easy for me as I have a small herb garden so fresh herbs are always accessible. But I can't do without fresh basil and rosemary. Basil, very versatile and handy, I use it to make pasta bakes, basil pesto and sometimes dips. No lamb can go without rosemary so I always have them on standby too.
This year we planted some parsley in the garden, but usually we stick to ground/dried herbs. The herbs I always keep on standby are parsley and basil because they go well with basically anything. As for spices I'll always make sure I have paprika and cinnamon at the ready. I find paprika a good alternative to chilli if I don't want to risk something being too hot, and cinnamon really enhances desserts and pastries.
Ground chipotle powder is the number one go-to spice in our household. It's just dried jalapeno peppers but it seems to go on almost everything. It has a way to making any meal taste 'smoked' or like bacon, I don't know why, but it's true!