It only ever worked when they were friendly, apparently that has changed and they can be neutral but everytime I have tried (quite often) its no.
So... just so you know what I do to help it along
- Naturally send a delegation on turn 1 of meeting
- Be very aware of their political agenda - no point trying to be friends with Trajan until later. This agenda is normally around +6 but sometimes +12 is great - Most important thing this.
- Send a trade route if you have one and need a couple of extra points (I normally do not bother) seems to degrade fairly fast too.
- Settle near them and agree not to do it again ... this starts as a -3 but turns into a +2 when you have kept your word 30 turns later... it then goes up to +3 before it degrades but it takes a while
- The one I like is once you have Early Empire .... put your open borders on the table and say what will you give me for it? ... they will normally pay gold for you to get +3 diplomacy with them! Ithink it degrades a point every 30
- Initial impressions degrades 1 point every 10 turns .. on Deity this can be -2 -8 at the start.. prince I think is +2 - -4 range... Never checked emp but 0 -6 range makes sense
- Look at their relationship with other civs ... find one that is denounced and denounce that civ too... this with the above is enough for friends
- Same as 7 but do a joint war... this is very very useful especially early on high levels... a very underrated tactic - went to war is about +5, not sure on degradation, not fast though
- A good deal can get you +10 but this degrades a point a turn so is pretty crappy unless you just need the short term push.
If you happen to get friends with Gilga he is like a protector and will often DOW people who DOW me.
Firiends then gives you +8 ... so if you have their agenda bonus its normally enough to have an alliance ... so really its all about agendas
*note... I never quite remember all the numbers some some may be slightly wrong.
Regarding diplo... another thing I noticed was that after a given amount of time, Norway lost the modifier for occupying Oslo. I had thought that modifier permanent.