How can i create leader lines to connect labels to symbology - formatting

Question

My Labels are crowded, I want to space them away from the points by add leader lines to make it clear which label is for which datapoint

Answer 1

You can use the "Easy Custom Label" plugin to do this.
EasyCustomLabeling is a plugin for QGIS, designed to simplify the work for manual and data defined labeling. The tool duplicates a data vector layer into a new memory layer made of lines, adds all necessary fields for advanced custom labeling like label location, rotation, color, font, callout, alignements. The resulting layer is activated ready to use labeling tools. Data is saved in Memory Layer provider, which means it is NOT saved to a file or a database. To make these layers persistent, please install Memory Layer Saver v3.2 or higher plugin, that saves all memory layers to a qdatastream file along the project named myqgisprojectname.qgs.mldata.
Once you have turned on the label toolbar you can press the easy label button to make a copy of the layer, you can then drag and drop any labels that you want to move and a leader line will be automatically added.

Answer 2

https://gist.github.com/kgjenkins/1af82a8ffdc3c99bb886e6cd9cdc298f
Callouts, sometimes called leader lines, are lines between labels and features on a map. They are useful when constraints of space force a label to be moved away from the feature. The callout helps to reconnect the label to the feature it refers to.
image
There are probably multiple ways to do this, but here is one way using a geometry generator in QGIS 3.x:
callouts_qgis
Turn on labels for the layer
•Style dock > Labels tab
•Change "No labels" to "Show labels for this layer"
•Select the field to "Label with"
Move individual labels
The upgrade to QGIS 3.0 has made label placement easier to customize. When you move a label, QGIS tracks the new location using hidden auxiliary storage fields that we'll use to draw the lines.
•Make sure the Label Toolbar is enabled (View menu > Toolbars)
•Select the "Move Label" tool image
•Click and drag the to move the labels. (The first time you click to move a label, you will be asked for a primary key to use for tracking the labels. Pick a field that has an id or otherwise unique values within your layer.)
Add the callout lines
•In the layer styling dock, click the green + to add a new marker component
•Set "Symbol layer type" to "Geometry generator"
•Set "Geometry Type" to "LineString / MultiLineString"
•Enter the following expression:
make_line(
make_point($x, $y),
make_point( "auxiliary_storage_labeling_positionx" , "auxiliary_storage_labeling_positiony" )
)
image
Improve the label display
•Add label buffers ("halos") so that the lines won't obscure the text of the label (3rd tab in the style dock)
•Adjust the label placement (6th tab in the style dock), data defined > alignment ◦set the horizontal alignment to 'Center'
◦set the vertical alignment to 'Half'