Often, part-timers are only interested in short contracts. In LLM I rarely look at anyone for longer than two year contract - as I am trying to improve the squad this seasons Key Player could well be next seasons Backup and it is easier to renegotiate when the contract is nearing it's end.
Also, if part-time, I tend to let them run to six months or less left before re-signing unless another club comes in for them.
Negotiate the **** out of them, seasonal landmarks can be good clauses, but make sure they are pretty much unattainable as your finances aren't going to be great. An optional extension is worth trying to get in there.
Watch the finances closely.
Part-time, lower league my approach is that everyone is on the transfer list (without having it set) if an offer comes in. I would be surprised if you can;t find a free-signing to replace any player pretty easily.
Watch the finances closely.
Once you are in negotiations, let the player show you what he wants, then talk him down. Unless he has improved significantly, try and keep his weekly wage the same or within 10-20% if he has improved, and sway him with bonuses etc. Again, "reaching Final of FA Trophy" or Winning It is a good one to use - chances are you won;t need to pay him out, but if you do get there, you have generated the funds from a cup run to pay it anyway. FA Cup bonuses are useful but always set a couple of rounds beyond your prediction/expectation.
Watch the finances closely.
I keep Promotion rises to a minimum - 10% ish, and the same for the dreaded 'yearly increase' - never more than 10% on a two-year deal, that way things don't spiral out of control.
Watch the finances closely.
Also, look at the player, try and guess what he wants out of it. Age is the biggie, the older they are the more they will want security so lean towards basic wage rather than bonus. Ambitious players may take lower basic with performance bonuses. Younger players get rewarded by me through performance, clean sheets/appearances etc or by a wage hike after 20 games - especially if they are professional or ambitious as this motivates a bit to get in the first team and also to perform.
Watch the finances closely.
Important thing to remember is that you can't win 'em all and some will 'Red Bar' you and refuse to negotiate any further. As I said before, a quick 'find similar' player search and there will be replacements available on a free, or at least out of contract at around the same time so just let them go. (You might even find a couple who will be cheaper for you anyway- Watch the finances closely.)
I found a good wage structure somewhere recently, and have implemented it in the Vanarama National save I have. Basically, in a squad of 25 players, 3 or 4 Key Players get 30% of the wage budget between them. 8-10 First Teamers get 30% between them, Rotation/Backups get 30% between them and youth players get the rest. Stick to that and you should be able to manage finances and hopefully your wage/transfer budget will get better - a good way to Watch the finances closely.