Still time to both vote tactically AND get a vote swap to get the Tories out. Use Swap my vote :)
If you're voting tactically (ie. not for your first choice but for the candidate best placed to beat the Tories), then why not amplify your vote by swapping with someone who will vote for your preference in a seat where it'll make more of a difference. For example, if you're a lib dem voting tactically in Battersea for Labour, try and find a lab voter in a Con/Lib fight like Richmond Park, Lewes or St Ives. It's almost a 2 for 1 remain deal, do it! https://www.swapmyvote.uk/