feel like a crap parent

[rhetorician]

my children just do whatever they want, have no respect for me or DP, ignore rules. They are both girls, 3 and 6. The elder one is particularly difficult. We have consequences, we follow through. it makes no discernible difference. We are clear about rules (there aren't that many of these - the obvious ones, I imagine). But a day at home is just a constant round of yelling, time outs, girls refusing to do things unless they are threatened, withdrawal of privileges, at which point they have no incentive to behave. I am running out of consequences. I do praise good behaviour, but they just don't seem to give a crap, frankly. And I am not enjoying it at all. Where to go from here?

Watching with interest. In exactly the same boat OP. I'm exhausted x

I have just told them that unless there is good behaviour tomorrow they will not be going to family party. BetteDavis?

I really wish I could teach DD1 to understand that if people are cross with her it's because she has done something wrong

Humble opinion and experience of my two boys who could drive me to distraction....

When it gets to this stage all the fun has gone between yourself and them. They relate to yourselves through a cycle of being told off and it becomes the norm.
Make sure you get quality time with each individually (dividing and conquering) that will not be removed if even if they've been naughty...usual removal of priveledges yes but this has to be sacred. They will enjoy time with you one and one and won't want you to be disappointed in them (rather keep you on side rather than make you cross). Along with individual time (uninterrupted by the other and it must be fun) factor in time for the four of you...again this can't be removed if naughty (sacred)..the time doesn't have to be expensive in fact the best times are doing things like baking and chatting or singing nursery rhymes etc...
Change doesn't happen overnight but it always worked for me. It used to be cycles where the boys would be good for a while and then play up and the common denominator to then playing up was when I'd under prioritised time individually and as a family that.
HTH

Do you give them your attention?

Hairylegs yes - lots of it. And lots of the kinds of things that wheely described. But it is 10pm and the 3 year old is still awake because her bed "smells of farts" and she will not give up until it is changed. It's not all negative attention - although it feels like it, but I can't let things like (1) taking all the soap from the bathroom (2) throwing toys into the chicken coop (3) pulling all the bedding off my bed and upturning the bin - all of which happened today - go unchallenged, surely? I let them away with quite a bit

No you can't let them things go...tough one.

I don't think that I punish things that they do unnecessarily - possibly the contrary (this is a legacy of DD1 reacting VERY badly to negativity/punishment) - maybe we need to go back to pasta jar type thing rewarding good behaviour?

Is thier bad behaviour a result of sleep deprivation?

I don't think so - tonight was particularly bad, but normally they are asleep by 8.30-9 and get up around 7.30-8 (school is finished now). They have tons of energy, don't seem tired - the last hour or so of nonsense is probably tiredness- and it does get worse towards the end of the day.

DD2 is naughty - but she is 3 and is mostly fairly ok, particularly when it's just her. DD1 is much more difficult (and of course DD2 follows her example) - will attempt to negotiate her way out of punishments, threatens ("I'll only do x if you let me do y"), even though several years of experience should have taught her that this doesn't work. She lost a whole week of screen time this week for throwing things and hitting, so it's not that I don't follow through. They watched no tv at bedtime today - screen privileges were restored this morning, so she did have some i-pad time this morning. Most of the day spent playing outside, bouncing on trampoline. Quick trip to town. They eat proper food, not many sweets.

You mention that holidays have started, I wonder if they are behaving like this because the routine has changed and the normal daily 'rules' and routine have relaxed? They may also be responding to having more energy as they are not at school/nursery.

I get this at the start of every holiday period until we both learn to adapt. Normally this means that I have to stay firm with routines eg get up in the morning and straight into 'day' clothes, no lounging around in PJ's. No lengthy fun breakfast food etc

havemercy yes, that's quite likely. Have started with pasta jar this morning and so far its working. At least it's better than yesterday...