Rhyming Timing

I have a dislike for repetition. If I have to do things repeatedly I get fed up and annoyed. I could never do a job that involved a lot of repetition and I admire those who can switch off and just do a job repeatedly for hours on end. I can't help it that's just the way I am. I find this attitude creeping into my poetry; I very seldom repeat a rhyme scheme exactly. In fact I some times get bored with rhyme all together. For some this is sacrilege. I know a poet that only ever writes four line stanzas that rhyme second and fourth line end words. Nothing wrong with that, except for me there's a sort of Status Quo feel about things so that you know what's coming next. It's a form of repetition.
Don't get me wrong, I have nothing against rhyme and I am a frequent user of it but I try to create my poems for their overall impact and construct them with that as my guiding principle. A lot can be done with the flow of reading scan or length of lines or alliteration without pairing up a single end word. But care must be taken to stay within the remit I set myself or otherwise I end up writing structured prose. The poetry that I like best often can be read so easily that you slide along the words and get to the end almost before you realise. I like my poems to have this quality and even deliberately disturb this polish to make point or catch the reader's attention. It's a bit like a stream flowing over a rock.
When to rhyme and when not to is a discussion that rages still and for me it's a personal choice about the poem. Often at the start of writing a poem I will not know whether the end product will have a defined rhyme scheme, but at some point I will stop myself and make choices about how I want the poem to be. Quite a few poems of mine have been stripped down and re written half way through. When you write do you plan first or during ? do you adhere to a rhyme structure or look for a style that fits the work. I would value your thoughts.

Peace Dave