Here we present some sensible principles and methods for defending against a strong club, followed by some consideration of other conventions on the market.
Strong hands pass: Passing initially, and then bidding shows a strong hand. This is, to some extent, true. For example, with a balanced 20 count start by passing, since there is no need to get in now, and then come in later to show the hand (either by doubling them or by bidding no trumps). However, with a good suit, it is still necessary to show the hand even if it is quite strong - if you pass now, you may later find yourself trying to guess what to do at a high level, and regretting not bidding your suit earlier.
Overcalls: I would recommend that overcalls are natural, and can be wide-ranging, with jump overcalls being weak. To cater for this, many people play that a 1NT response to an overcall shows support - that is, a bid designed to show that you have some support for partner, and a fair hand. Since you have no cue available you cannot make a more normal `unassuming cuebid'.
CRO: Standing for `Colour Rank Other,' this signifies the possible two suiters you can have. With two suits of the same colour, you double; with two of the same rank (ie majors or minors) you bid one diamond (the exception to overcalls being natural); and with any other two suiter (ie the pointed or rounded suits), you bid 1NT. Some people also play 2NT as majors or minors in addition to this (but more of them).
Partner then bids suits as `pass or convert,' meaning that he only passes if he has the suit you have bid. With this scheme it is common to play that a 1NT (or 2NT) response suggests that partner has a suit of his own he wants to play in.
The main problems with CRO are the fact that you lose the diamond overcall, that you don't know immediately which suits partner has, and that it can give away much information during the play. Against this, it gives very little away to opponents during the bidding, and conveniently shows all the two suited hands.
Fourth hand defence: After 1-P-1, many people simply play that everything is natural, except that double shows the majors, and 1NT shows the minors.
Escaping when doubled: The general principle is that all redoubles are SOS - ie they suggest that you do not play in the current contract! There are also other principles, often similar to those after partner has done a takeout double. For example, if the auction commences 1-1-P-P, X-P-P (or 1-X-XX), then you use 1NT as being initially natural, but then if that is doubled, you have the option of redoubling to show the minors, or bidding a minor to show that minor as well as hearts.
Other defences: There are a plethora of other defences, many having reasonable merit. I would be reluctant to play a defence such as Truscott (double shows diamonds and spades, 1NT shows clubs and hearts, and suit bids show that suit and the one above), since it removes the very useful major suit overcalls, which is the thing you most often want to do over a strong club. (Similarly when defending against 1NT, it is vital to be able to show a single suited major suit.)
More useful (though not always licensed), are defences such as Amsbury or Panama, where bids show several options. For example, a defence I often play when not vulnerable, is that a two level overcall shows a good suit in the suit bid, or a weak one in the one above. Such a defence you cannot really afford to play when vulnerable, since it relies on the fact that you will not mind going six off playing in their suit if not doubled, as you hope they have game on. At the same time it can be very difficult to defend against, as they often have no idea which suit you have, and so have no cuebid.
Older Precision members of the County may still recall my days of partnering Philip Wood, when we played the Amsbury defence. Philip would solemnly and precisely announce `That shows a single suiter in the suit bid, or a three suiter excluding the suit bid, or a touching two suiter in principle anchoring to the locally lower link weaker suit.' Work that one out! Most Cambridge Club pairs had a special defence against this - they bid 3NT!