Advice on savings/investments with long-term and short term split

I am looking for some advice in terms of strategy for investing and saving and the split between short term and long term. Ive been doing a bit of research and reading some posts on this forum but obviously everyone’s situation is different and any helpful advice or just personal experience/opinions would be much appreciated.

I’m not completely financially illiterate and aware of the risks and rewards of investing but haven’t done much in the past and not fully up to speed with what is best in terms of which funds, platforms, LISA vs normal S&S ISA and just a trading account (outside of GCT and dividend tax savings when above the thresholds, which are fairly high on an annual basis)

Some info about me to help tailor advice:

Aged 33, full time employed and higher rate tax payer. I currently contribute to a work placed pension and can increase this but my employer won’t go beyond the 2% they currently match for now (pretty low from them IMO but anyway it is what it is).

I currently have a bit of savings in a relatively high interest rate regular saver (5% AER), some P2P lending and a few grand emergency savings, which if they all return as expected will put me round about the £500 interest tax free allowance threshold.

I currently own a flat with my other half so I don’t need to save for a deposit but as our current place was a first step on the ladder, a move in the next 2/3 years could happen. We’ve done a fair bit of work on the flat so no big expenditure on current place is expected.

After paying my mortgage, bills, all other food and leisure activities plus holidays, I should have about £1,000 per month to put into further savings and/or investments. So the question is what is a good strategy for the £1kpm?

I’m happy to lock some away for a longer period of time (higher contribution to pension, LISA, S&S ISA?).

I also want to keep a proportion available in the short term in case needed (stamp duty/deposit in a couple of years, emergency, wedding maybe!) but I’d like to gain the best return, whilst still being to access if and when needed. Don’t know if that is just pumping more into as much higher rate savings and taking a tax hit above the £500 threshold.

Does anyone have some helpful advice on how to balance some long term savings with trying to get the best returns on fairly accessible savings/investments? (I’m aware that investments in S&S ISA would be liquid but potentially cashing out if needed during a downtown could lead to taking a hit.

Thanks and sorry for the long post..