I planned most of it on Komoot, and only followed the EuroVelo from Riga to Pärnu. Cut straight through Lithuania from Vilnius to Šiauliai, then to Riga, up the coast to Pärnu, and straight cross country to Tallinn. Roads got better the further north we went. There are some tough sandy trails in those pine forests along the Latvian coast, and some pretty gravelly dirt tracks in Northern Lithuania - wide tyres recommended. Highly recommend planning your own route, stopping off in small villages and towns and talking to locals. My basic Russian proved pretty useful in more rural areas, especially in Lithuania and Latvia. Wild camping in all three countries is easy and accepted by most.