Next steps to build my property portfolio?

Firstly, I have to say “I love this platform”, thank you all so much. A brilliant resource which I often find myself reading for hours on end rather than getting on with work! Oh, and in ref to a comment this week I don’t really care if my questions sound naive!

My question is about the next steps with my very, very small portfolio and looking at what is the best way to finance next steps.

In total I have 4 properties, all paid for with cash and with no outstanding mortgages/debts. All are in tip top condition inside and outside. Three are based near Newcastle, 2x 1 bed apartments and 1x 3 bed duplex apartment. The remaining property is a 2 bed, 2 bath apartment directly on the beach and is based in the Isle of Man. All are rented out.

What do you think would be the best way to move forward and buy a couple more BTL properties? 

The initial reasoning for purchasing outright was to relax and not worry too much if the properties were empty for any length of time as they all had major refurbs, financially things were a bit rocky for everyone and also hearing horror stories of whole portfolios being on finance and landlords loosing the whole lot.

It’s worth noting property is a long term strategy for me (10-15yrs) and this is not my main income, however, I enjoy the whole process of refurbishing however large. I always need a project!

Ideas, however radical, all welcome.

Thanks.

Angela