I think it's critical that you need to learn how to use snaps, Nigel. With snaps, your endpoints are connected as you draw them, there's no need to trim or join afterwards at all. TC is what's called "feature-based" CAD, and snaps connect lines, arcs and curves, which are themselves features, to other features. When you open a new drawing with no figures in it, the only features that exist in the drawing are the coordinate system and the grid that derives from it. The "features" that snaps recognise and connect to are grid intersections, points (vertices), which are line end points, and all you have to do is move your cursor to somewhere near the point that you want to connect to, and press the G key for a grid intersection or V key for a line endpoint, the line or whatever should connect to it immediately. If you're not close enough to it, or there's ambiguity, a message or a "ding" sound tells you so. Lines have other features too, mid-point accessed with the M key, divide points accessed with D (you can specify how many divisions from the "snap" and "geo" boxes below the drawing window), and nearest point on the line to the cursor, with N. Then there are features that apply to other figures, a circle's centre which is accessed with C (but you've gotta hover the cursor over the target circle's perimeter, not it's centre), Q for its quadrant points.
You can also use "running snaps", where the snaps are active all the time and give you visual cues on-screen (flickering red x or diamond outline) when your cursor is in proximity to the feature, or have snaps inactive but invoke them with TC's Single Entry Key Equivalent (SEKE) when you recognise the proximity yourself, which is one of TC's greatest usability strengths. When I started using TC, I found TC's much more fluid than others' systems, but even in other CAD systems, snaps are equally vital.
They're perhaps the most important part of CAD, because they're used in every part of it. They ensure precision when performing any action, so they ensure the efficiency of every action by making after-the-fact editing unnecessary. No problems like integrity of hatch regions or even untidiness. Use them always and everything you do will be easier.