Boundaries: How to change 'The Rules of the Game', (with example..)

Figure out what is it EXACTLY that is bugging you about something that person does.
It's usually a recurring event.
When you are at home, doing your own thing and AWAY FROM THAT PERSON OR SITUATION, decide what 'alternative arrangement' you would prefer. What 'other thing' would you like?
DO NOT ATTEMPT TO ASSERT BOUNDARIES IN THE HEAT OF THE MOMENT OR WHEN YOU ARE 'AMBUSHED' ON THE SPOT.
Make the request into a POLITE REQUEST STATEMENT. This may take a while to figure out exactly as tact and consideration are involved.
DO NOT ATTEMPT TO FIGURE OUT THIS SENTENCE IF YOU ARE RILED OR FEELING BITTER as your sentence will sound riled and bitter!
There's a great deal of skill in making polite requests in such a way THAT DOES NOT OFFEND OR BLAME.
Blaming is rubbish and just creates more problems. Besides, as AA tells us, we are usually TALKING OUT OF OUR A**E when we are angry. Well I am anyway! I don't know about you. I always think I am a demented Looney frothing at the mouth when I am experiencing anger. Even if the thing that I am objecting to is TOTALLY AWFUL BEHAVIOUR.
Why do I think that? Because you never see the Dalai Lama lose the rag with the Chinese. That's why. Now there IS a sane individual!

Ok. Plan your 'request statement' IN ADVANCE. And just 'wait in the undergrowth' for the person to do the thing THAT REALY ANNOYS YOU again. They will! They always do! You could probably set your watch by it!
Next time you chat to them, just wait for the SAME OLD SAME OLD to come up again.
Then REALLY CASUALLY, just drop in IN A VERY 'OFF THE CUFF', 'MATTER OF FACT WAY' your prepared SENTENCE. MAKE IT AS SHORT AS POSSIBLE. NO LONG WINDED, MEANDERING, TRAILING OFF SENTENCES.
SHORT AND SWEET. NO DRAMA. NO BLAME. NO RECRIMINATION.
CALM AS A CUCUMBER.

No doubt they will probably seem momentarily surprised. They might go 'Oh'.
SEIZE the MOMENT. DO NOT LET THEM START A LONG DEBATE ON WHY? OR PULL YOU OFF TRACK.
Before they get a chance to counter, debate, or argue the point, just say 'Yeah, I'd much prefer it if you could do that, I know it might seem a bit weird! Is that ok?
'ok'
Cool. (Job done!)

Then the NEXT time they do it, (They ALWAYS do!) you just need to smile and give them THAT LOOK and say 'Remember that conversation we had?' they say 'oh yes'. You say , 'Well then I wont need to repeat myself then, will I? (I always try to do these things in good humor, with a friendly smile)
'No'
'Good'.
(Done!)
See? No drama!

Why do I know this, BECAUSE I FORGOT MY 'RULES OF ENGAGEMENT' recently, and did it in a 'clunky' way instead. Doh! See I don't meet ANY boundary crashers these days, and so I had forgotten my ROUTINE.

Oh well
I'll give you MY example to show you how I SHOULD have done it.

Problem. Nosey Girlfriend (not on a 'spiritual path' as such.) I used to talk to her about 'guy stuff', both hers and mine. But although I knew she meant well insofar as she tried very hard to find solutions for me, I found her feedback and ensuing questions increasingly irritating. I was not happy with her MOTIVE on both counts.
I felt her motive to FIX was coming from her INABILTY TO TOLERATE DIFFICULTY, and I suspected her motive for REPEATEDLY asking me about my state of affairs was GRATUITOUS CURIOSITY. Either way, it wasn't working.

So what I SHOULD have said was...
(Me) ' You know X, I know you really care about me, and in truth you have been a very loyal and reliable friend to me, but I'm afraid I would MUCH rather PREFER IT if you STOPPED asking about these things when we get together.
If there's something I REALLY think you NEED TO KNOW, I WILL tell you. But in the meantime, PLEASE stop questioning me about it. Ok?'

Dissent of some sort. 'Oh don't be silly, sure I'm only asking' etc

(Me) 'Really. I would really appreciate it if you would do that from now on.'

If continued dissent..

(Me) 'If its any help, I used to get upset when girlfriends didn't tell me ALL about their personal stuff. I fell out with someone a while back over it. I was pretty mad! Since then I have learned that THEY ARE UNDER NO OBLIGATION TO TELL ME ANYTHING. And I respect that. Sorry if that seems strange to you. It seemed strange to ME when I was mad at MY friend. But I can see it differently now, and I take an entirely different view.
Of COURSE we're still friends! Its just for the time being I would prefer it if you stop asking me about this.'

Even if you are feeling REALLY PISSED OFF by their objections or protestations. DO NOT SHOW IT. Be CALM AND REASONABLE. But NOT a APOLOGETIC DOORMAT. Just don't froth at the mouth or say something WITHOUT THINKING when you are 'mad'. BECAUSE YOU WILL PROBABLY SAY SOMETHING CLUMSY AND BADLY THOUGHT OUT. Ie CRAP!
End.

Do you see?
The trick is TO HAVE A PLAN. WORD FOR WORD. PREPARED IN ADVANCE.
Yet ANOTHER example of 'you snooze you lose'
Life is not for sissies or lightweights! We have to pay attention EVERY DAY. And there are NO days off!! If we don't get these things RIGHT we just CREATE MORE PROBLEMS FOR OURSELVES. Ah well..

CLUMSY, unkind speech is SO easy to do, when we are angry, because we just aren't very good at THINKING CLEARLY and OBJECTIVELY when our blood is boiling... We always end up doing a very second class job of it..

See I could have just said MIND YOUR OWN EFFING BUSINESS YOU NOSEY COW. JESUS IF YOU ASK ME ONE MORE FREAKING TIME I WILL NOT BE RESPONSIBLE FOR WHAT I DO!!.
But that would have ESCALATED the problems somewhat!!!!
Hahaaaa hhaa Sorry I know that's really cheeky but I just thought that was funny. I couldn't resist putting that in... lol
Sorry if that seems terribly 'unspiritual', but I use lots of irreverent, cheeky speech (mostly to myself) to have a laugh about things when something is annoying me. Its one of my 'tricks' for changing my mood. Humor is very powerful. (Not in a way that hurts someone, only in a 'third party' way)

Also if they get nasty. I get firmer and more business-like. Otherwise I keep the mood as light as possible.
If they become antisocial, I leave them alone with a phrase along the lines of 'I think we should leave this for now and continue this conversation when you have cooled down'. Then I LEAVE. I don't tolerate any CRAZYNESS. Loonies ranting or frothing at the mouth NEED TO BE LEFT ALONE! But I very rarely have to deal with this.

Anyway, hope that helps you understand the whole boundary thing. I do it another way too, but this is my main method.