Anyway here are some things I've noticed while playing FM12, that might be usefull to know. All following should work on the latest patch.
1. Set players' value to 0. Players or their agents will not become upset when you reject a bid of 0. Also, no one will bid higher than 0, and thus will not meet possible release clause fees as long as the clause fees are higher than 0.
2. You actually can reject bids that meet a release clause fee. At least when there are multiple bids not all of them triggering a release clause (actually this is the only scenario I've had the chance to test this so far). To reject any bid, click “reject all unresponded offers” in transfer center.
3. Try to sign players on bosman transfer. Players are usually more interested in negotiating a contract with you when they still have not left their clubs at the end of their contracts, than when they have just become unattached.
4. Monitor recently released unattached players. Unattached players will continuously lower their demands. After a few months they will accept contracts with much lower wage from clubs with considerably lower reputation than right after they were released.
5. Do not shortlist players. This is usefull with previous tip. If you shortlist a player, other clubs are more likely to become interested in signing him. Instead of shortlisting a player, bookmark him, and then click the star icon on the top right to subscribe to him so you still get news if someone offers him a cntr.
6. Use trials. Players on trial with you will usually be more interested in joining you/have lower contract demands.
7. Scout all regens. Well, maybe not all but many anyways. The point is to scout them immediately after they have appeared before others have them under contract. In most European leagues new players will appear during March.
If you are a lower league club, use player search to filter all unattached players who are 16 or younger and send your scouts to look at them. If you have large/huge db, there could be loads of free youngsters to scout, but if you are using smaller db there might be just a few. Anyway, this way you could be able sign a real gem even if your club is in BSR (or equivalent). If you manage a club with high rep, use player search to filter all players 16 or younger who are at clubs in Premier Division and Championship (or equivalent), and scout them. You might be able to sign a talented youngster on very short notice - youth players who have not yet signed any kind of contract with their current club are more likely to be interested in joining other clubs. The key again is to quickly identify the most talented players and have them sign a contract with you rather than the club where they came through the youth system.
Sjálfur er ég ekki ennþá kominn í það að þjálfa neðri deildarlið í FM12 en ætli maður reyni ekki við English Hero fljótlega :)