inkscape tutorial - create a union of different objects

When I work in inkscape it's often helpful to create a union of different objects. This is similar to grouping them, but rather than creating a group of different objects, a union functions as one object. This is useful if you have many small objects in a design like the dots on my rosehips below.

Inkscape seems to be a bit buggy when it comes to very large files with many groups of objects. Reducing the number of groups helps when working with large designs.

Step 1: Decide which objects you want to create a union with. All the little dots on the rosehips are single objects. I want to be able to manipulate the colours more quickly, and want lines of dots to function as single objects so that I can more easily change colours and move the dots around.
Step 2: Select all the objects.
Step 3: Under path click on union. Or use the keyboard shortcut CMD +
Step 4: The row of dots now functions as one object. Change the colour, or move the object to a different position.

ps. do you like the pattern? Its one I've been working on the last few weeks. I'll share more when its done.