Start with the right bread.

Good bread does not have to be expensive, but it should suit the filling. Soft sliced bread works with delicate fillings; a seeded loaf supports cheese, chutney and roast meats; rolls and baguettes cope well with generous fillings; wraps suit chopped ingredients; and pittas are useful for leftovers that would otherwise tumble out.

• Choose a sturdy bread for wet or substantial fillings.
• Use softer bread for egg, cucumber or cream-cheese combinations.
• Toast bread only when the sandwich will be eaten fairly soon; toast can become tough when refrigerated overnight.
• Let frozen bread thaw completely before filling it.

Create a moisture barrier.

I keep salted butter in a butter dish, although in winter it can still be too firm to spread without tearing the bread. Cream cheese or a thin layer of mayonnaise works just as well. Spread it lightly and right to the edges: it adds flavour, prevents dry corners and creates a barrier between the bread and wetter ingredients.

Drain tomatoes, pickles, mozzarella and dressed fillings well. If the sandwich must wait several hours, place lettuce, cheese or sliced meat against the bread and keep tomatoes, chutney or dressed ingredients closer to the centre.

Spread every layer to the edges.

Every bite should contain the sandwich you intended to make. Spread sauces thinly across the whole slice and distribute the main filling evenly rather than building a mound in the centre. Be generous enough that the filling can be tasted, but not so ambitious that half of it lands in your lap.

Layer it so it stays together.

1. Spread both slices lightly to create an even barrier.
2. Add a flat, sturdy layer such as cheese, lettuce or sliced meat.
3. Place softer or wetter filling in the middle.
4. Add herbs, crisp vegetables or seasoning evenly.
5. Finish with another stable layer before closing.
6. Press gently, then cut with a sharp serrated knife.

Sandwiches that survive overnight.

Cheese and chutney, ham and mustard, coronation chicken, corned beef and pickle, or chicken with crisp peppers usually hold well overnight when packed correctly. Delicate leaves, juicy tomatoes and very wet fillings are better added in the morning or carried separately.

Wrap the sandwich snugly and refrigerate it promptly. Store opened meats and cheeses properly too; dried edges are wasted food as well as poor sandwich material.

Wraps, pittas and open sandwiches.

A wrap is useful when you have several small ingredients to use, but fold the lower edge in firmly before rolling so the filling cannot escape. Pittas contain loose leftovers particularly well, while open sandwiches make smaller amounts of a special topping feel more substantial.

• Chilli-stuffed mini pittas with sour cream and cheddar
• Better packed lunches: easy ideas that save money

Combinations worth trying.

For a vegan version, use plant-based bread and spreads, then build flavour with hummus, beans, tofu, avocado, roasted vegetables, pickles, herbs and toasted seeds.