Improving lord relations with quests

I'm working on improving my relationships with a number of lords in one of my current saves. So far, I've been fighting alongside them, echoing their opinions on who should receive the next fief, etc, and it's been going well... however, I'd also like to start completing quests in order to build up good relationships faster with a few specific lords.

The problem that I keep running into is that, aside from the occasional dinky "deliver this letter please" quests, many of the requests that the lords make are nearly impossible for me to complete. I'm a relatively new vassal with one fief and an army of 85 soldiers; capturing 10 Mamelukes isn't going to happen, and I absolutely cannot afford to give up a significant number of Huscarls over and over again. Capturing an enemy lord seems reasonable, but since it's completely random, it might not happen before the current war is over. Hell, I might capture one only to have him escape before I can make it back!

What makes this issue even worse is that refusing the offered quests seems to make me take a nice little -2 hit to the relationship in question, which has made me stop asking altogether. Is there any way to get more reasonable quests, or should I forget about the option entirely?

I just ahve some tips in mind :
-For the lord capture mission, accept it : you gain +1 relation by accepting it, and you have 30 days to do it : the war will probably end before the quest, so if you fail you keep a free +1
-If there's a quest you don't want, accept it, so other lords won't give it again to you (you can't have 2 identical quests at the same time)

I guess that makes sense. I'll try it out.

Thanks.

Same with the capture troops quest; just accept them and given that it gives you 60 days, war will be over and no negative hit.