How to draw dashed, dotted and arrowed lines in Layout
Use the Stroke panel in Layout by Zaweba to set dashes, dots, gaps and arrowheads, then save named stroke styles that update every line using them.

Draw the line, then set its look in the Stroke panel of Layout by Zaweba. The panel offers solid, dashed with your own dash and gap, dotted, thick-thin, thin-thick, triple, wavy, hash and straight hash types, plus start and end arrowheads with their own scale. For a look you'll use again, define a named stroke style under Object > Stroke styles and every line that uses it updates when you change it.
Lines do a lot of quiet work in a layout. A dotted rule separates entries in a programme, a dashed line marks where to cut a coupon, an arrow points to a detail on a diagram. Getting them consistent across a document is what makes them look intentional.
The Stroke panel
Select a line or a frame, and the Stroke panel shows its settings. Weight sets thickness. Cap decides how the ends look and join decides how corners meet, with a miter limit for sharp corners. Align puts the stroke on the centre of the path, inside it or outside it, which matters for frames where you want the outer size to stay exact.
Type is where dashes and dots live. Choose dashed and set the dash and gap lengths to suit; short dashes and long gaps make a light, open line, while long dashes and short gaps read almost as solid. Dotted gives round dots. The double and triple types, such as thick-thin, make classic decorative rules, and wavy and hash types suit borders and playful designs.
Gaps don't have to be empty. You can give the gap a colour and tint, so a dashed line can alternate between two colours.
Adding arrowheads
Arrowheads go at the start, the end or both, and each has a scale so the head can be larger or smaller relative to the line. Draw a line from where the arrow starts to where it points, set an end arrowhead, and it points the right way. If it's backwards, swap the start and end settings rather than redrawing.
For diagrams, keep arrowhead scale the same across the document. Mixed sizes look careless even when nobody can say why.
Named stroke styles
Object > Stroke styles lets you define your own dashes, dots and stripes and give them names. Apply a style from the Stroke panel, and every line using it changes when you edit the style. A cut line, a map route or a form's dotted fill-in line can each have a style, so they look the same on every page. Stroke styles can be loaded from other documents, which keeps a series of publications consistent.
There's a print detail too: a line's gap colour can be set to overprint. Ask your printer whether that suits the job.
Lines that print cleanly
Use swatches for line colours, not unnamed colours, so they separate properly and change everywhere at once. For print, very thin lines in a light tint can break up; choose a slightly heavier weight or a stronger colour.
Watch dashes on corners. On a rectangle, a dash pattern may not land neatly at each corner; try adjusting the dash and gap lengths, or the join, until the corners look even.
Live preflight checks the document as you work, and the separations preview shows how lines will print on each ink, which is useful for fine rules in spot colours.
Other drawing tools that help
Lines drawn with the Pen and Pencil tools are real Bézier paths, so you can reshape a curved arrow after you've styled it. Corner options round or shape the corners of frames, and the same stroke settings apply to them. For decoration, the Effects panel adds shadows and glows to lines as well as shapes.
With strokes set up as styles, Layout by Zaweba keeps every dotted rule and arrow in a document looking like it came from the same hand.