I guess it all depend on what kind of Job you are applying to!
my personal experience tells me there's nothing much different in a job interview in lithuania, from other countries, unless it's a requirement to speak Lithuanian for that job I guess.
I went through some interviews for different I.T positions, programmer, DBA, system admin. ..etc
I was trying to be just my self yet in a professional way, I did actually refuse some jobs for different reasons, and I was patient enough to finally find what I was looking for and that's a good thing for me and the company am working for.
so don't rush over all to accept the 1st job you get accepted to, you really need to like it, like the place you are going to be working in, the people you are going to be working with..etc
for these kind of jobs there's almost no dress code as long as it's not really out of line
used to go with jeans T-shirts, nothing so formal yet the normal, but remember in such a job I wouldn't normally be dealing with clients directly as in lets say sales, marketing, customer support..etc, sometime we do but not the norm.
so the dress code is some what casual.
So for those trying to nail a job in Lithuania, do your homework regarding what kind of job you will be doing, search online regarding usual formalities, dress codes...etc and when it comes to Lithuania I personally didn't see anything out of the usual.