I presume it's obvious but I'll say it anyway, accurate layout and marking on the wood is an all-important first step.
I have used my jigsaw or chisel for similar cuts on other projects. While I wasn't aiming for high precision on those projects, it seems too sloppy to achieve the precision for cabinetry.
I wouldn't myself do these kinds of cuts using a jigsaw, but it is possible though. People successfully use jigsaws to cut deep overlapping cross-lap joints for knockdown plywood furniture and that requires quite a high degree of accuracy.
Some of the tips given for doing clean, straight cuts with a jigsaw are:
- run the baseplate along a straight edge clamped in place (just a good straight piece of 1x2 is all that's needed)
- work slowly, if you force the cut it can tend to induce flex in the blade
- use a good quality blade (some are also capable of giving good surfaces on both sides of the material, although many are designed to give good top or bottom surfaces)
- if you can't find or afford a suitable blade it's worth deeply knifing your layout lines on both sides to prevent chipout
I would do these sorts of cuts by hand and a sharp chisel would play a big part in the process, especially for cleaning up the corners but often for a bit of fine-tuning of the straight cuts, paring back to my gauged lines.
If one of the difficulties you experienced when paring with a chisel was holding it consistently vertical it's worth using a guide block clamped in place that the flat of the chisel can ride against:
Guide blocks can also be used to help ensure square shoulders when sawing as shown in this pair of illustrations which I think originally came from a Jackson/Day book:
I have just purchased a good table saw and router, and am a complete novice with them. I have thought about standing the board on edge and cutting in to get a clean cut, using a dado or many passes for the edge notch, but that seems awkward and quite dangerous.
Yes that could be quite dangerous with a table saw!
A router can be used quite easily to do these sorts of cut-outs. A jig or template would make the cuts very accurate and repeatable, if you don't mind having to construct them ahead of time. The jigs would be much like those in the following pic, made for doing the recess to take a hinge:
The cut-out in the template is made a little oversize (by a fixed amount so easy to make the necessary adjustments to your measurements) and a collar/guide bush projecting from the base of the router will follow along its inside edge.
If you're cutting through the full thickness of the material in one pass turn the speed on the router up to full and progress the cut at a measured pace, do not attempt to force it to cut.
Rounded corners: a router will naturally produce rounded internal corners, which are usually squared up. This is commonly done with a chisel, but you can also use a corner chisel or the 'shell' of a mortising bit.
If you don't fancy doing that you can actually leave the corners round. For the toe-kick especially I don't see an advantage to making the corner square and having it rounded is less usual so you could consider it a feature.
With the front notch that will accept the horizontal board you would have to round over a short portion of the two inside edges of the board to get it to fit in the notch properly. This isn't particularly difficult, although you may want to practice once or twice on scraps before doing it for real. Again after carefully marking out to start with you can do this by paring (using a chisel, carving knife, sharp penknife), paring then sanding, just by sanding or with a file, whatever you prefer.