Happily, we don't have many insect pests in our garden, at least bothersome ones -- maybe milkweed bugs on milkweed pods (quite cool -- they're only on the pods), localized aphids occasionally, squash vine borers on summer squash, and an occasional Japanese beetle. And I don't mind occasional small munches taken from leaves, actually (although big herbivores are in another category).
I'm thinking that diversity of plantings is probably the key, since we have so many different species of trees, shrubs, and herbs, no big beds of one thing, lots of natives, and hardy non-natives. We also don't ever fertilize anything, except for the vegetables, only adding leaf mulch and other organic mulches. So, there's not extra succulent nitrogen-rich foliage to attract leaf-chomping insects.
As we've created our woodland and shrub borders, layers of vegetation have developed, just like in a 'natural' forest, providing cover for MANY more bird species over the years. (When it was primarily lawn, we didn't see much activity!) But, with a variety of birds, many are actively foraging for insects at different times of the year, sometimes just when they're supporting nestlings and fledglings.
In the vegetable garden, I mix up the blocks for both attractiveness and diversity, and figure that helps, too.
More problematic are some of the common problems that afflict less-resistant sorts of tomatoes, peppers, and beans. In the original main garden, rotation was pretty haphazard, and not really possible not to repeat tomatoes, peppers, and brassicas in the same space, especially since I'm doing intensive successional change-outs, even when adding lots of compost each time (often a recommendation for disease suppression). By adding the satellite garden as a permanent bed area, I have a bit more scope, so I'm trying to be a better record keeper about what's been planted where and when.
It doesn't seem like a huge garden area, although I suppose it's relative. The main vegetable garden is made up of 5 blocks roughly 4' X 5' each, with a long strip along the fence (1 1/2' X 20'). The satellite garden has 7 beds of varying sizes, ranging from 3' X 4' to 3' X 7' to 2 1/2' X 8'. Obviously, I wasn't very methodical with these as I made them 'permanent' -- although I've evened them out a bit, as I've amended them each season and added mulched paths and stone edging.
So I spent some time this afternoon mapping out the vegetables in each of the beds, and nicely labeled each on my garden map. I've seen some pretty elaborate schemes for tracking rotations (using Excel files, charting programs, etc.), all of which sound like more work than fun to me, but again, some people like to keep detailed records more than others. But the basics of plant rotation are simple -- not planting members of the same plant families in the same place in successive years. By mixing up what's planted in each bed, it's more complicated to figure out the rotations, too, but maybe mixes up the pests and diseases as well.