Check the MSA of the area...presumably you had a map AND KNOW WHERE YOU ARE...try restoring the battery first ,for the a/hzn/t-slip,and HSI.Check the OAT/ICING,try a radio,and/or the ILS(have you a Jepp.chart for base ,or anywhere...? As you should have plenty of fuel,do all this in VMC...if you have an ELT/PLB,TURN IT ON,IT MAY HAVE A VOICE CHANNEL,and people will know you have a problem...someone may be able to come and be a `formation `lead`down the ILS....Do the radio/instruments/ils work or have you any electric power...at a minimum you need the `turn & slip`...conserve electric power in VMC...
My plan would depend on the ILS if I can position to join it at 8000ft/30 miles(300ft/mile),U/C down,1/2 flap,carb air,pitot htr on,DVpanel slightly open ,so I can judge the airspeed,having checked the `standby compass and t/slip,descent power.
Plan `B`,would be similar if I went out to sea if no electrics..
Plan `C` would be to put on my parachute and jump before reaching the coast.....